The gettext module does not entirely cleanup after itself in
its GRUB_MOD_FINI() leaving a few variables hooks in place.
It is not possible to unload gettext module because normal
module depends on it. Though fix the issues for completeness.
Fixes: CVE-2025-0622
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>