Doxygenize the existing comments without altering the actual contents of the

comment.

Originally committed as revision 8246 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/rtp.h

@@ -27,7 +27,7 @@
 int rtp_init(void);
 int rtp_get_codec_info(AVCodecContext *codec, int payload_type);
 
-/* return < 0 if unknown payload type */
+/** return < 0 if unknown payload type */
 int rtp_get_payload_type(AVCodecContext *codec);
 
 typedef struct RTPDemuxContext RTPDemuxContext;