avcodec: use cast to avoid warning about this const. It's a rare case where we...

avcodec: use cast to avoid warning about this const. It's a rare case where we use a dummy empty palette that won't change and we don't want to recreate it every time either.

modules/codec/avcodec/video.c

@@ -337,7 +337,7 @@ int InitVideoDec( decoder_t *p_dec, AVCodecContext *p_context,
         p_sys->p_context->palctrl =
             (AVPaletteControl *)p_dec->fmt_in.video.p_palette;
     else if( p_sys->i_codec_id != CODEC_ID_MSVIDEO1 && p_sys->i_codec_id != CODEC_ID_CINEPAK )
-        p_sys->p_context->palctrl = &palette_control;
+        p_sys->p_context->palctrl = (AVPaletteControl *) &palette_control;
 
     /* ***** Open the codec ***** */
     vlc_mutex_t *lock = var_AcquireMutex( "avcodec" );