serial: mxs-auart: put the device in mxs_auart_probe()

We call the get_device() in the mxs_auart_probe().
For the balance of the reference count, we should put the
device in the mxs_auart_remove().

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index ea5f888..6898413 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -796,6 +796,7 @@
 
 	auart_port[pdev->id] = NULL;
 
+	put_device(s->dev);
 	clk_put(s->clk);
 	free_irq(s->irq, s);
 	kfree(s);