All callers pass a dict argument to @keys, except check_keys() passes
a dict's .keys(). Drop .keys() there, and rename parameter @keys to
@value.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190914153506.2151-16-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>