drm/ttm: Fix a few sparse warnings

The final parameter to ttm_bo_reserve() is a pointer, therefore callers
should use NULL instead of 0.

Fixes a bunch of sparse warnings of this type:

	warning: Using plain integer as NULL pointer

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 5d6a875..957d4fa 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -362,7 +362,7 @@
 {
 	int ret;
 
-	ret = ttm_bo_reserve(&bo->bo, true, no_wait, false, 0);
+	ret = ttm_bo_reserve(&bo->bo, true, no_wait, false, NULL);
 	if (ret) {
 		if (ret != -ERESTARTSYS && ret != -EBUSY)
 			DRM_ERROR("reserve failed %p\n", bo);
diff --git a/drivers/gpu/drm/bochs/bochs_fbdev.c b/drivers/gpu/drm/bochs/bochs_fbdev.c
index 19cf3e9..fe95d31 100644
--- a/drivers/gpu/drm/bochs/bochs_fbdev.c
+++ b/drivers/gpu/drm/bochs/bochs_fbdev.c
@@ -72,7 +72,7 @@
 
 	bo = gem_to_bochs_bo(gobj);
 
-	ret = ttm_bo_reserve(&bo->bo, true, false, false, 0);
+	ret = ttm_bo_reserve(&bo->bo, true, false, false, NULL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c
index b3c6130..9d7346b 100644
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@@ -53,7 +53,7 @@
 	if (old_fb) {
 		bochs_fb = to_bochs_framebuffer(old_fb);
 		bo = gem_to_bochs_bo(bochs_fb->obj);
-		ret = ttm_bo_reserve(&bo->bo, true, false, false, 0);
+		ret = ttm_bo_reserve(&bo->bo, true, false, false, NULL);
 		if (ret) {
 			DRM_ERROR("failed to reserve old_fb bo\n");
 		} else {
@@ -67,7 +67,7 @@
 
 	bochs_fb = to_bochs_framebuffer(crtc->primary->fb);
 	bo = gem_to_bochs_bo(bochs_fb->obj);
-	ret = ttm_bo_reserve(&bo->bo, true, false, false, 0);
+	ret = ttm_bo_reserve(&bo->bo, true, false, false, NULL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/gpu/drm/cirrus/cirrus_drv.h b/drivers/gpu/drm/cirrus/cirrus_drv.h
index 117d3ec..401c890 100644
--- a/drivers/gpu/drm/cirrus/cirrus_drv.h
+++ b/drivers/gpu/drm/cirrus/cirrus_drv.h
@@ -241,7 +241,7 @@
 {
 	int ret;
 
-	ret = ttm_bo_reserve(&bo->bo, true, no_wait, false, 0);
+	ret = ttm_bo_reserve(&bo->bo, true, no_wait, false, NULL);
 	if (ret) {
 		if (ret != -ERESTARTSYS && ret != -EBUSY)
 			DRM_ERROR("reserve failed %p\n", bo);
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
index cf11ee6..80de23d 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.h
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
@@ -280,7 +280,7 @@
 {
 	int ret;
 
-	ret = ttm_bo_reserve(&bo->bo, true, no_wait, false, 0);
+	ret = ttm_bo_reserve(&bo->bo, true, no_wait, false, NULL);
 	if (ret) {
 		if (ret != -ERESTARTSYS && ret != -EBUSY)
 			DRM_ERROR("reserve failed %p\n", bo);
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index b6dc85c..ba29a70 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -309,7 +309,7 @@
 	struct ttm_buffer_object *bo = &nvbo->bo;
 	int ret;
 
-	ret = ttm_bo_reserve(bo, false, false, false, 0);
+	ret = ttm_bo_reserve(bo, false, false, false, NULL);
 	if (ret)
 		goto out;
 
@@ -350,7 +350,7 @@
 	struct ttm_buffer_object *bo = &nvbo->bo;
 	int ret, ref;
 
-	ret = ttm_bo_reserve(bo, false, false, false, 0);
+	ret = ttm_bo_reserve(bo, false, false, false, NULL);
 	if (ret)
 		return ret;
 
@@ -385,7 +385,7 @@
 {
 	int ret;
 
-	ret = ttm_bo_reserve(&nvbo->bo, false, false, false, 0);
+	ret = ttm_bo_reserve(&nvbo->bo, false, false, false, NULL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index c90c0dc..df9d451 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -61,7 +61,7 @@
 	if (!cli->base.vm)
 		return 0;
 
-	ret = ttm_bo_reserve(&nvbo->bo, false, false, false, 0);
+	ret = ttm_bo_reserve(&nvbo->bo, false, false, false, NULL);
 	if (ret)
 		return ret;
 
@@ -132,7 +132,7 @@
 	if (!cli->base.vm)
 		return;
 
-	ret = ttm_bo_reserve(&nvbo->bo, false, false, false, 0);
+	ret = ttm_bo_reserve(&nvbo->bo, false, false, false, NULL);
 	if (ret)
 		return;
 
diff --git a/drivers/gpu/drm/qxl/qxl_object.h b/drivers/gpu/drm/qxl/qxl_object.h
index d458a14..83a4232 100644
--- a/drivers/gpu/drm/qxl/qxl_object.h
+++ b/drivers/gpu/drm/qxl/qxl_object.h
@@ -31,7 +31,7 @@
 {
 	int r;
 
-	r = ttm_bo_reserve(&bo->tbo, true, no_wait, false, 0);
+	r = ttm_bo_reserve(&bo->tbo, true, no_wait, false, NULL);
 	if (unlikely(r != 0)) {
 		if (r != -ERESTARTSYS) {
 			struct qxl_device *qdev = (struct qxl_device *)bo->gem_base.dev->dev_private;
@@ -67,7 +67,7 @@
 {
 	int r;
 
-	r = ttm_bo_reserve(&bo->tbo, true, no_wait, false, 0);
+	r = ttm_bo_reserve(&bo->tbo, true, no_wait, false, NULL);
 	if (unlikely(r != 0)) {
 		if (r != -ERESTARTSYS) {
 			struct qxl_device *qdev = (struct qxl_device *)bo->gem_base.dev->dev_private;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c
index 70ddce835..ed1d510 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c
@@ -61,7 +61,7 @@
 
 	vmw_execbuf_release_pinned_bo(dev_priv);
 
-	ret = ttm_bo_reserve(bo, interruptible, false, false, 0);
+	ret = ttm_bo_reserve(bo, interruptible, false, false, NULL);
 	if (unlikely(ret != 0))
 		goto err;
 
@@ -105,7 +105,7 @@
 	if (pin)
 		vmw_execbuf_release_pinned_bo(dev_priv);
 
-	ret = ttm_bo_reserve(bo, interruptible, false, false, 0);
+	ret = ttm_bo_reserve(bo, interruptible, false, false, NULL);
 	if (unlikely(ret != 0))
 		goto err;
 
@@ -212,7 +212,7 @@
 
 	if (pin)
 		vmw_execbuf_release_pinned_bo(dev_priv);
-	ret = ttm_bo_reserve(bo, interruptible, false, false, 0);
+	ret = ttm_bo_reserve(bo, interruptible, false, false, NULL);
 	if (unlikely(ret != 0))
 		goto err_unlock;
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index f31a754..18b54aca 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -316,7 +316,7 @@
 	if (unlikely(ret != 0))
 		return ret;
 
-	ret = ttm_bo_reserve(bo, false, true, false, 0);
+	ret = ttm_bo_reserve(bo, false, true, false, NULL);
 	BUG_ON(ret != 0);
 
 	ret = ttm_bo_kmap(bo, 0, 1, &map);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index 991e5c8..d2bc2b0 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -136,7 +136,7 @@
 	kmap_offset = 0;
 	kmap_num = (width*height*4 + PAGE_SIZE - 1) >> PAGE_SHIFT;
 
-	ret = ttm_bo_reserve(&dmabuf->base, true, false, false, 0);
+	ret = ttm_bo_reserve(&dmabuf->base, true, false, false, NULL);
 	if (unlikely(ret != 0)) {
 		DRM_ERROR("reserve failed\n");
 		return -EINVAL;
@@ -343,7 +343,7 @@
 	kmap_offset = cmd->dma.guest.ptr.offset >> PAGE_SHIFT;
 	kmap_num = (64*64*4) >> PAGE_SHIFT;
 
-	ret = ttm_bo_reserve(bo, true, false, false, 0);
+	ret = ttm_bo_reserve(bo, true, false, false, NULL);
 	if (unlikely(ret != 0)) {
 		DRM_ERROR("reserve failed\n");
 		return;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index 01d68f0..a432c0d 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -127,7 +127,7 @@
 	if (res->backup) {
 		struct ttm_buffer_object *bo = &res->backup->base;
 
-		ttm_bo_reserve(bo, false, false, false, 0);
+		ttm_bo_reserve(bo, false, false, false, NULL);
 		if (!list_empty(&res->mob_head) &&
 		    res->func->unbind != NULL) {
 			struct ttm_validate_buffer val_buf;