rmdec: Improve message for demux error

Use correct context, reduce log level, don't assume it is a video stream,
and print the tag of the unknown stream.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

libavformat/rmdec.c

@@ -313,7 +313,7 @@ int ff_rm_read_mdpr_codecdata(AVFormatContext *s, AVIOContext *pb,
         int fps;
         if (avio_rl32(pb) != MKTAG('V', 'I', 'D', 'O')) {
         fail1:
-            av_log(st->codec, AV_LOG_ERROR, "Unsupported video codec\n");
+            av_log(s, AV_LOG_WARNING, "Unsupported stream type %08x\n", v);
             goto skip;
         }
         st->codec->codec_tag = avio_rl32(pb);