Revert "platform/x86: wmi: Destroy on cleanup rather than unregister"

This reverts commit 7b11e89.

Consider the following hardware setting.

|-PNP0C14:00
|  |-- device #1
|-PNP0C14:01
|  |-- device #2

When unloading wmi driver module, device #2 will be first unregistered.
But device_destroy() using MKDEV(0, 0) will locate PNP0C14:00 first
and unregister it. This is incorrect. Should use device_unregister() to
unregister the real parent device.

Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>
Link: https://lore.kernel.org/r/20191115052710.46880-1-yongxin.liu@windriver.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/wmi.c

@@ -1347,7 +1347,7 @@ static int acpi_wmi_remove(struct platform_device *device)
 	acpi_remove_address_space_handler(acpi_device->handle,
 				ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
 	wmi_free_devices(acpi_device);
-	device_destroy(&wmi_bus_class, MKDEV(0, 0));
+	device_unregister((struct device *)dev_get_drvdata(&device->dev));
 
 	return 0;
 }
@@ -1401,7 +1401,7 @@ static int acpi_wmi_probe(struct platform_device *device)
 	return 0;
 
 err_remove_busdev:
-	device_destroy(&wmi_bus_class, MKDEV(0, 0));
+	device_unregister(wmi_bus_dev);
 
 err_remove_notify_handler:
 	acpi_remove_notify_handler(acpi_device->handle, ACPI_DEVICE_NOTIFY,