Fix inheritdoc for interfaces
Fix inheritdoc for interfaces

In some situations the method returned to early. This solves that issue
by checking all levels and return null at the end.

rgeraads/phpDocumentor2,rgeraads/phpDocumentor2,phpDocumentor/phpDocumentor2,mbed67/phpDocumentor2,jaapio/phpDocumentor2,phpDocumentor/phpDocumentor2,rgeraads/phpDocumentor2,jaapio/phpDocumentor2,mbed67/phpDocumentor2,mbed67/phpDocumentor2,phpDocumentor/phpDocumentor2,mbed67/phpDocumentor2,jaapio/phpDocumentor2,rgeraads/phpDocumentor2,phpDocumentor/phpDocumentor2,jaapio/phpDocumentor2