of: unittest: Drop call to platform_set_drvdata(..., NULL)

The driver core already unsets driver data after .remove() completes.
So there is no reason to do this explicitly in the driver itself.

Signed-off-by: Uwe Kleine-König <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Herring <[e-mail]>

drivers/of/unittest.c

···
 	if (devptr->chip.base != -1)
 		gpiochip_remove(&devptr->chip);
 
-	platform_set_drvdata(pdev, NULL);
 	kfree(devptr);
 
 	return 0;