I got tired of fixing this in Renesas drivers manually, so I took the big
hammer. Remove this cumbersome code pattern which got copy-pasted too much
already:
I have been asked if it couldn't be done for dev_set_drvdata as well. I checked
it and did not find one occasion where it could be simplified like this. Not
much of a surprise because driver_data is usually set in probe() functions
which access struct platform_device in many other ways.
I am open for other comments, suggestions, too, of course.