roqvideodec: replace dead code by assert

Fixes CID732195
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/roqvideodec.c

@@ -25,6 +25,7 @@
  *   http://www.csse.monash.edu.au/~timf/
  */
 
+#include "libavutil/avassert.h"
 #include "avcodec.h"
 #include "bytestream.h"
 #include "roqvideo.h"
@@ -149,7 +150,7 @@ static void roqvideo_decode_frame(RoqContext *ri)
                     }
                     break;
                 default:
-                    av_log(ri->avctx, AV_LOG_ERROR, "Unknown vq code: %d\n", vqid);
+                    av_assert2(0);
             }
         }