debug: tell how much bits are skipped with unknown nal code

Originally committed as revision 9993 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -7853,7 +7853,7 @@ static int decode_nal_units(H264Context *h, uint8_t *buf, int buf_size){
         case NAL_AUXILIARY_SLICE:
             break;
         default:
-            av_log(avctx, AV_LOG_ERROR, "Unknown NAL code: %d\n", h->nal_unit_type);
+            av_log(avctx, AV_LOG_ERROR, "Unknown NAL code: %d (%d bits)\n", h->nal_unit_type, bit_length);
         }
     }