landlock: Simplify current_check_access_socket()

Remove the handled_access variable in current_check_access_socket() and
update access_request instead.  One up-to-date variable avoids picking
the wrong one.

Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Link: https://lore.kernel.org/r/20240307093923.1466071-1-mic@digikod.net


Signed-off-by: Mickaël Salaün <mic@digikod.net>