check_keys() has become a trivial wrapper for check_known_keys(). Eliminate it. This makes its name available. Rename check_known_keys(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20190927134639.4284-24-armbru@redhat.com>