staging: android: timed_output: fix use after free of dev

tdev->dev has been freed in device_destroy(), it's not right to
use dev_set_drvdata() after that;
Signed-off-by: Yi Zhang <yizhang@marvell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/timed_output.c

@@ -97,7 +97,6 @@ void timed_output_dev_unregister(struct timed_output_dev *tdev)
 {
 	tdev->enable(tdev, 0);
 	device_destroy(timed_output_class, MKDEV(0, tdev->index));
-	dev_set_drvdata(tdev->dev, NULL);
 }
 EXPORT_SYMBOL_GPL(timed_output_dev_unregister);