Bluetooth: hci_nokia: Use new hci_uart_unregister_device() function

Simplify _remove() path for hci_nokia.c

Signed-off-by: Ian Molton <[e-mail]>
Reviewed-by: Sebastian Reichel <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

drivers/bluetooth/hci_nokia.c

···
 static void nokia_bluetooth_serdev_remove(struct serdev_device *serdev)
 {
 	struct nokia_bt_dev *btdev = serdev_device_get_drvdata(serdev);
-	struct hci_uart *hu = &btdev->hu;
-	struct hci_dev *hdev = hu->hdev;
 
-
-	hci_unregister_dev(hdev);
-	hci_free_dev(hdev);
-
-	cancel_work_sync(&hu->write_work);
-
-	hu->proto->close(hu);
+	hci_uart_unregister_device(&btdev->hu);
 }
 
 static int nokia_bluetooth_runtime_suspend(struct device *dev)