[texture] Avoid redundant use of cogl_clip_stack_save when drawing offscreen

Since cogl draw buffers now own their clip state the stage's clip state will
automatically be saved and restored via the cogl_set_draw_buffer API.

clutter/clutter-texture.c

@@ -586,15 +586,9 @@ clutter_texture_paint (ClutterActor *self)
 		  COGL_BUFFER_BIT_DEPTH);
       cogl_disable_fog ();
 
-      /* Clear the clipping stack so that if the FBO actor is being
-	 clipped then it won't affect drawing the source */
-      cogl_clip_stack_save ();
-
       /* Render out actor scene to fbo */
       clutter_actor_paint (priv->fbo_source);
 
-      cogl_clip_stack_restore ();
-
       /* Restore drawing to the frame buffer */
       cogl_set_draw_buffer (COGL_WINDOW_BUFFER, COGL_INVALID_HANDLE);