fixed: playing mpegts over rtsp caused ffmpeg to read uninitialized s…

…tack values

This is an amendment to cdfab91 the memleak
fix for mpegts. It's questionable if that change is needed. Since
the main issue it was for has been fixed correctly. However it
doesn't hurt to avoid potential memleaks this way.

lib/ffmpeg/libavformat/mpegts.c

@@ -1879,6 +1879,7 @@ int ff_mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,
 
     len1 = len;
     ts->pkt = pkt;
+    ts->pkt->data = NULL;
     ts->stop_parse = 0;
     for(;;) {
         if (ts->stop_parse>0)