drm/vmwgfx: Don't access file_priv in cursor_set when handle==0

We want to disable the cursor by calling ->cursor_set() with handle=0
from places where we don't have a file_priv, so don't try to access it
unless necessary.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/vmwgfx/vmwgfx_kms.c

@@ -174,7 +174,6 @@ int vmw_du_crtc_cursor_set(struct drm_crtc *crtc, struct drm_file *file_priv,
 			   uint32_t handle, uint32_t width, uint32_t height)
 {
 	struct vmw_private *dev_priv = vmw_priv(crtc->dev);
-	struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
 	struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
 	struct vmw_surface *surface = NULL;
 	struct vmw_dma_buffer *dmabuf = NULL;
@@ -197,6 +196,8 @@ int vmw_du_crtc_cursor_set(struct drm_crtc *crtc, struct drm_file *file_priv,
 	}
 
 	if (handle) {
+		struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
+
 		ret = vmw_user_lookup_handle(dev_priv, tfile,
 					     handle, &surface, &dmabuf);
 		if (ret) {