avformat/mpegts: Fix side data type for stream id

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit ab1319d8)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mpegts.c

@@ -887,7 +887,7 @@ static void new_data_packet(const uint8_t *buffer, int len, AVPacket *pkt)
 
 static int new_pes_packet(PESContext *pes, AVPacket *pkt)
 {
-    char *sd;
+    uint8_t *sd;
 
     av_init_packet(pkt);