TT#14008 fix possible use-after-free

Change-Id: I454d07f339e689bbc349ffef774ded6ef163e985
(cherry picked from commit aae30a4f72)

daemon/codec.c

@@ -1752,6 +1752,9 @@ static int __handler_func_sequencer(struct media_packet *mp, struct transcode_pa
 	atomic64_inc(&ssrc_in->packets);
 	atomic64_add(&ssrc_in->octets, mp->payload.len);
 
+	// save RTP pointer - we clobber it below XXX this shouldn't be necessary to do
+	struct rtp_header *orig_rtp = mp->rtp;
+
 	packet->p.seq = ntohs(mp->rtp->seq_num);
 	packet->payload = str_dup(&mp->payload);
 	uint32_t packet_ts = ntohl(mp->rtp->timestamp);
@@ -1840,6 +1843,8 @@ out:
 	__ssrc_unlock_both(mp);
 	obj_put(&ch->h);
 
+	mp->rtp = orig_rtp;
+
 	return 0;
 }