HBAC: Enforce coding style ipa_hbac_rule_info_recv()
    
    By convention, the output variables are prefixed with a underscore.
    
    Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>
    
    Reviewed-by: Pavel Březina <pbrezina@redhat.com>
    Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>