lib: fix warnings in fallback set_time logic

Fix the build time warnings:

safe_file_ops.c: In function 'safe_touch':
safe_file_ops.c:237:4: warning: passing argument 2 of 'set_time' discards 'const' qualifier from pointer target type [enabled by default]
safe_file_ops.c:165:13: note: expected 'struct timespec *' but argument is of type 'const struct timespec *'
safe_file_ops.c:239:4: warning: passing argument 2 of 'set_time' discards 'const' qualifier from pointer target type [enabled by default]
safe_file_ops.c:165:13: note: expected 'struct timespec *' but argument is of type 'const struct timespec *'

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/lib/safe_file_ops.c b/lib/safe_file_ops.c
index b5075c7..0325ce2 100644
--- a/lib/safe_file_ops.c
+++ b/lib/safe_file_ops.c
@@ -162,7 +162,7 @@
 
 #ifndef HAVE_UTIMENSAT
 
-static void set_time(struct timeval *res, struct timespec *src,
+static void set_time(struct timeval *res, const struct timespec *src,
 			long cur_tv_sec, long cur_tv_usec)
 {
 	switch (src->tv_nsec) {
@@ -211,7 +211,7 @@
 	}
 
 
-#if HAVE_UTIMENSAT
+#ifdef HAVE_UTIMENSAT
 	ret = utimensat(AT_FDCWD, pathname, times, 0);
 #else
 	if (times == NULL) {