use utimes instead of utimensat/futimens

cppcheck complains about the obsolete utime as it was removed in
POSIX1.2008 and recommends usage of utimensat/futimens instead
as those are in POSIX and so commit 9ce3cfc9 switched to them.
It is just that they aren't as portable as the standard suggests:
At least our kFreeBSD and Hurd ports stumble over it at runtime.
So to make both, the ports and cppcheck happy, we use utimes instead.

Closes: 738567