Do not crash in vout destruction when exiting

src/video_output/video_output.c

@@ -508,9 +508,11 @@ static void vout_Destructor( vlc_object_t * p_this )
 
 #ifndef __APPLE__
     vout_thread_t *p_another_vout;
-    playlist_t *p_playlist = pl_Yield( p_vout );
 
-    /* This is a dirty hack for mostly Linux, where there is no way to get the GUI
+    playlist_t *p_playlist = pl_Get( p_vout );
+    if( p_playlist->b_die ) return;
+    vlc_object_yield( p_playlist );
+/* This is a dirty hack for mostly Linux, where there is no way to get the GUI
    back if you closed it while playing video. This is solved in Mac OS X,
    where we have this novelty called menubar, that will always allow you access
    to the applications main functionality. They should try that on linux sometime */