rtsp: Make sure we don't write too many transport entries into a fixed-size array

CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/rtsp.c

@@ -972,6 +972,8 @@ static void rtsp_parse_transport(RTSPMessageHeader *reply, const char *p)
             p++;
 
         reply->nb_transports++;
+        if (reply->nb_transports >= RTSP_MAX_TRANSPORTS)
+            break;
     }
 }