Drop AVERROR_NOTSUPP at the next major bump, use AVERROR(ENOSYS)

instead which is semantically equivalent.

See the thread:
Subject: [FFmpeg-devel] [RFC] The meaning of AVERROR_NOTSUPP
Date: Sat, 27 Mar 2010 00:51:13 +0100

Originally committed as revision 22981 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/error.c

@@ -27,7 +27,6 @@ int av_strerror(int errnum, char *errbuf, size_t errbuf_size)
     switch (errnum) {
     case AVERROR_EOF:               errstr = "End of file"; break;
     case AVERROR_INVALIDDATA:       errstr = "Invalid data found when processing input"; break;
-    case AVERROR_NOTSUPP:           errstr = "Operation not supported"; break;
     case AVERROR_NUMEXPECTED:       errstr = "Number syntax expected in filename"; break;
     case AVERROR_PATCHWELCOME:      errstr = "Not yet implemented in FFmpeg, patches welcome"; break;
     }

libavutil/error.h

@@ -43,12 +43,12 @@
 #define AVERROR_NOENT       AVERROR(ENOENT)  ///< No such file or directory
 #define AVERROR_NOFMT       AVERROR(EILSEQ)  ///< Unknown format
 #define AVERROR_NOMEM       AVERROR(ENOMEM)  ///< Not enough memory
+#define AVERROR_NOTSUPP     AVERROR(ENOSYS)  ///< Operation not supported
 #define AVERROR_NUMEXPECTED AVERROR(EDOM)    ///< Number syntax expected in filename
 #define AVERROR_UNKNOWN     AVERROR(EINVAL)  ///< Unknown error
 #endif
 
 #define AVERROR_EOF         AVERROR(EPIPE)   ///< End of file
-#define AVERROR_NOTSUPP     AVERROR(ENOSYS)  ///< Operation not supported
 
 #define AVERROR_PATCHWELCOME    (-MKTAG('P','A','W','E')) ///< Not yet implemented in FFmpeg, patches welcome