drm/vmwgfx: Drop drm_vblank_cleanup

Again stopping the vblank before uninstalling the irq handler is kinda
the wrong way round, but the fb_off stuff should take care of
disabling the dsiplay at least in most cases. So drop the
drm_vblank_cleanup code since it's not really doing anything, it looks
all cargo-culted.

v2: Appease gcc better.

v3: Simplify code (Sean Paul)

Cc: Sinclair Yeh <syeh@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170626161949.25629-1-daniel.vetter@ffwll.ch
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index a8876b0..5fab9ed 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -1771,7 +1771,7 @@ int vmw_kms_init(struct vmw_private *dev_priv)
 
 int vmw_kms_close(struct vmw_private *dev_priv)
 {
-	int ret;
+	int ret = 0;
 
 	/*
 	 * Docs says we should take the lock before calling this function
@@ -1779,11 +1779,7 @@ int vmw_kms_close(struct vmw_private *dev_priv)
 	 * drm_encoder_cleanup which takes the lock we deadlock.
 	 */
 	drm_mode_config_cleanup(dev_priv->dev);
-	if (dev_priv->active_display_unit == vmw_du_screen_object)
-		ret = vmw_kms_sou_close_display(dev_priv);
-	else if (dev_priv->active_display_unit == vmw_du_screen_target)
-		ret = vmw_kms_stdu_close_display(dev_priv);
-	else
+	if (dev_priv->active_display_unit == vmw_du_legacy)
 		ret = vmw_kms_ldu_close_display(dev_priv);
 
 	return ret;