Remove definition of match_ext(), which is declared under #ifdef

HAVE_AV_CONFIG_H and so not publicly declared, and currently unused.

Originally committed as revision 22353 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/utils.c

@@ -142,13 +142,6 @@ void av_register_output_format(AVOutputFormat *format)
     format->next = NULL;
 }
 
-#if LIBAVFORMAT_VERSION_MAJOR < 53
-int match_ext(const char *filename, const char *extensions)
-{
-    return av_match_ext(filename, extensions);
-}
-#endif
-
 int av_match_ext(const char *filename, const char *extensions)
 {
     const char *ext, *p;