timestamp is dts in wmv/asf

Originally committed as revision 15821 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/asf.c

@@ -791,7 +791,7 @@ static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)
             /* new packet */
             av_new_packet(&asf_st->pkt, asf->packet_obj_size);
             asf_st->seq = asf->packet_seq;
-            asf_st->pkt.pts = asf->packet_frag_timestamp;
+            asf_st->pkt.dts = asf->packet_frag_timestamp;
             asf_st->pkt.stream_index = asf->stream_index;
             asf_st->pkt.pos =
             asf_st->packet_pos= asf->packet_pos;