drm/vmwgfx: Annotate ignored return values

Cast return values to void since they, based on input arguments,
are known to be zero.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
index c894a48..c7cf48c 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
@@ -839,7 +839,7 @@ static void vmw_move_notify(struct ttm_buffer_object *bo,
  */
 static void vmw_swap_notify(struct ttm_buffer_object *bo)
 {
-	ttm_bo_wait(bo, false, false);
+	(void) ttm_bo_wait(bo, false, false);
 }
 
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index be35385..541a588 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -1293,7 +1293,7 @@ static void __vmw_svga_enable(struct vmw_private *dev_priv)
  */
 void vmw_svga_enable(struct vmw_private *dev_priv)
 {
-	ttm_read_lock(&dev_priv->reservation_sem, false);
+	(void) ttm_read_lock(&dev_priv->reservation_sem, false);
 	__vmw_svga_enable(dev_priv);
 	ttm_read_unlock(&dev_priv->reservation_sem);
 }
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index 8e86d6d..65b3f03 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -1760,7 +1760,7 @@ void vmw_resource_unpin(struct vmw_resource *res)
 	struct vmw_private *dev_priv = res->dev_priv;
 	int ret;
 
-	ttm_read_lock(&dev_priv->reservation_sem, false);
+	(void) ttm_read_lock(&dev_priv->reservation_sem, false);
 	mutex_lock(&dev_priv->cmdbuf_mutex);
 
 	ret = vmw_resource_reserve(res, false, true);
@@ -1770,7 +1770,7 @@ void vmw_resource_unpin(struct vmw_resource *res)
 	if (--res->pin_count == 0 && res->backup) {
 		struct vmw_dma_buffer *vbo = res->backup;
 
-		ttm_bo_reserve(&vbo->base, false, false, NULL);
+		(void) ttm_bo_reserve(&vbo->base, false, false, NULL);
 		vmw_bo_pin_reserved(vbo, false);
 		ttm_bo_unreserve(&vbo->base);
 	}