ovl: don't fail copy up if no fileattr support on upper

ovl: don't fail copy up if no fileattr support on upper

commit 94fd19752b28aa66c98e7991734af91dfc529f8f upstream.

Christoph Fritz is reporting that failure to copy up fileattr when upper
doesn't support fileattr or xattr results in a regression.

Return success in these failure cases; this reverts overlayfs to the old
behavior.

Add a pr_warn_once() in these cases to still let the user know about the
copy up failures.

Reported-by: Christoph Fritz <chf.fritz@googlemail.com>
Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags")
Cc: <stable@vger.kernel.org> # v5.15
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>