vout_ReleasePicture: do not wake up the video output thread

The video output thread never allocates pictures from the decoder
thread. It uses the reserve private pool and, when if not rendering
directly, the display pool. Thus it has nothing particular to do when
a decoder pool picture is released.

(vout_PutPicture() wakes the thread up to kick rendering.)

src/video_output/video_output.c

@@ -461,8 +461,6 @@ void vout_ReleasePicture(vout_thread_t *vout, picture_t *picture)
     picture_Release(picture);
 
     vlc_mutex_unlock(&vout->p->picture_lock);
-
-    vout_control_Wake(&vout->p->control);
 }
 
 /**