quoted

* Is it still correct nowadays that the function "gigaset_initcs" did not
  call the function "kfree" after a later function call failed?

Yes, if it is handled in another place, Paul already did show you the place.

To which source code place do you refer here?

quoted

* Do you expect that allocated memory will be automatically reclaimed
  after it would return a null pointer?

Of course not

Thanks for this acknowledgement.

Regards,
Markus