modules.openbsdservice: avoid shadowing outer enabled() func

```
************* Module salt.modules.openbsdservice
salt/modules/openbsdservice.py:234: [W0621(redefined-outer-name), get_enabled] Redefining name 'enabled' from outer scope (line 240)
salt/modules/openbsdservice.py:268: [W0621(redefined-outer-name), get_disabled] Redefining name 'enabled' from outer scope (line 240)
```