Simplify check state handling

Data functions and special functions cannot be checked at all, so
there is no need to inherit the state by its parent.

Change-Id: If72f79ef6bcd77628916bd7fbe137faa5555db41
Reviewed-by: Niels Weber <niels.weber@theqtcompany.com>
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>