serial: uartlite: fix null dereference on probe error path

The `pdata->ulite_uart_driver` is assigned last in the probe function. So,
when un-registering the serial device on the error path this causes a
null dereference and a crash.

This fixes that by passing the initialized `ulite_uart_driver` pointer.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

drivers/tty/serial/uartlite.c

@@ -953,7 +953,7 @@ static int ulite_probe(struct platform_device *pdev)
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 err_out_unregister_driver:
-	uart_unregister_driver(pdata->ulite_uart_driver);
+	uart_unregister_driver(ulite_uart_driver);
 err_out_id:
 	mutex_lock(&bitmap_lock);
 	clear_bit(pdata->id, bitmap);