avformat/utils: Drop unused goto label.

libavformat/utils.c:2165:2: warning: label ‘fail’ defined but not used

libavformat/utils.c

@@ -2162,7 +2162,6 @@ static int try_decode_frame(AVStream *st, AVPacket *avpkt, AVDictionary **option
             pkt.size -= ret;
         }
     }
- fail:
     return ret;
 }