avformat/apc: Remove unnecessary resetting of flags

The packet a demuxer receives is freshly initialized, hence it is
unnecessary to reset any flags on them (as none are set), yet apc did
this.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/apc.c

@@ -78,7 +78,6 @@ static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)
         return AVERROR(EIO);
-    pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
     pkt->stream_index = 0;
     return 0;
 }