avformat/mux: Don't unnecessarily zero-initialize AVPacketList

If no error occurs and this AVPacketList is used at all, its packet
substructure will be overwritten and its next pointer explicitly set, so
every field will still be initialized even when using av_malloc.

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

libavformat/mux.c

@@ -931,7 +931,7 @@ int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
     AVStream *st   = s->streams[pkt->stream_index];
     int chunked    = s->max_chunk_size || s->max_chunk_duration;
 
-    this_pktl      = av_mallocz(sizeof(AVPacketList));
+    this_pktl      = av_malloc(sizeof(AVPacketList));
     if (!this_pktl)
         return AVERROR(ENOMEM);
     if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {