avformat/avidec: don't save a copy of the packet's AVBufferRef on DV streams

It's no longer needed.

Signed-off-by: James Almer <jamrial@gmail.com>

libavformat/avidec.c

@@ -1494,10 +1494,8 @@ resync:
         }
 
         if (CONFIG_DV_DEMUXER && dv_demux) {
-            AVBufferRef *avbuf = pkt->buf;
             size = avpriv_dv_produce_packet(avi->dv_demux, pkt,
                                             pkt->data, pkt->size, pkt->pos);
-            pkt->buf    = avbuf;
             pkt->flags |= AV_PKT_FLAG_KEY;
             if (size < 0)
                 av_packet_unref(pkt);