Replace ENOSYS by ENOTSUP as in this case the problem is not really a function

which is not available, but a media type which is not supported.

Originally committed as revision 9768 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/vocenc.c

@@ -34,7 +34,7 @@ static int voc_write_header(AVFormatContext *s)
 
     if (s->nb_streams != 1
         || s->streams[0]->codec->codec_type != CODEC_TYPE_AUDIO)
-        return AVERROR(ENOSYS);
+        return AVERROR(ENOTSUP);
 
     put_buffer(pb, voc_magic, sizeof(voc_magic) - 1);
     put_le16(pb, header_size);