rtp sout: fix comment

modules/stream_out/rtp.c

@@ -1576,7 +1576,7 @@ static int64_t rtp_init_ts( const vod_media_t *p_media,
     /* As per RFC 2326, session identifiers are at least 8 bytes long */
     strncpy((char *)&i_ts_init, psz_vod_session, sizeof(uint64_t));
     i_ts_init ^= (uintptr_t)p_media;
-    /* Limit the timestamp to 48 bytes, this is enough and allows us
+    /* Limit the timestamp to 48 bits, this is enough and allows us
      * to stay away from overflows */
     i_ts_init &= 0xFFFFFFFFFFFF;
     return i_ts_init;