wrapper.c: delete dead function git_mkstemps()

Its last call site was replaced by mks_tempfile_ts() in 284098f (diff:
use tempfile module - 2015-08-12) and there's a good chance
mks_tempfile_ts will continue to successfully handle this job. Delete
it.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -926,8 +926,6 @@ static inline int is_empty_blob_sha1(const unsigned char *sha1)
 
 int git_mkstemp(char *path, size_t n, const char *template);
 
-int git_mkstemps(char *path, size_t n, const char *template, int suffix_len);
-
 /* set default permissions by passing mode arguments to open(2) */
 int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
 int git_mkstemp_mode(char *pattern, int mode);

wrapper.c

@@ -446,23 +446,6 @@ int git_mkstemp(char *path, size_t len, const char *template)
 	return mkstemp(path);
 }
 
-/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
-int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
-{
-	const char *tmp;
-	size_t n;
-
-	tmp = getenv("TMPDIR");
-	if (!tmp)
-		tmp = "/tmp";
-	n = snprintf(path, len, "%s/%s", tmp, template);
-	if (len <= n) {
-		errno = ENAMETOOLONG;
-		return -1;
-	}
-	return mkstemps(path, suffix_len);
-}
-
 /* Adapted from libiberty's mkstemp.c. */
 
 #undef TMP_MAX