mfd: Use to_platform_device instead of container_of

Convert mfd_remove_devices_fn() to use to_platform_device()
instead of doing container_of().

Signed-off-by: Ben Dooks <[e-mail]>
Acked-by: Dmitry Baryshkov <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/mfd-core.c

···
 
 static int mfd_remove_devices_fn(struct device *dev, void *unused)
 {
-	platform_device_unregister(
-			container_of(dev, struct platform_device, dev));
+	platform_device_unregister(to_platform_device(dev));
 	return 0;
 }