Input: ab8500-ponkey - remove redundant platform_set_drvdata()

Commit 0998d06310 (device-core: Ensure drvdata = NULL when no
driver is bound) removes the need to set driver data field to
NULL.

Signed-off-by: Sachin Kamat <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/misc/ab8500-ponkey.c

···
 	input_unregister_device(ponkey->idev);
 	kfree(ponkey);
 
-	platform_set_drvdata(pdev, NULL);
-
 	return 0;
 }