video: Replace one vlc_object_find() with input_GetVout

src/control/video.c

@@ -42,7 +42,7 @@ static vout_thread_t *GetVout( libvlc_media_player_t *p_mi,
 
     if( p_input_thread )
     {
-        p_vout = vlc_object_find( p_input_thread, VLC_OBJECT_VOUT, FIND_CHILD );
+        p_vout = input_GetVout( p_input_thread );
         if( !p_vout )
         {
             libvlc_exception_raise( p_exception, "No active video output" );