aic_bridge: Flag an unused parameter.

modules/stream_out/mosaic_bridge.c

@@ -627,6 +627,7 @@ static picture_t *video_new_buffer( vlc_object_t *p_this,
                                     decoder_owner_sys_t *p_sys,
                                     es_format_t *fmt_out )
 {
+    VLC_UNUSED(p_this);
     if( fmt_out->video.i_width != p_sys->video.i_width ||
         fmt_out->video.i_height != p_sys->video.i_height ||
         fmt_out->video.i_chroma != p_sys->video.i_chroma ||