vfs: allow utimensat() calls to retry once on an ESTALE error

Clearly, we can't handle the NULL filename case, but we can deal with
the case where there's a real pathname.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --cc fs/utimes.c
Simple merge