serial: mxs-auart: Disable clock on error path

We should disable the previously acquired clock when enabling s->clk
fails.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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 2f04ec2..680270b 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -1543,10 +1543,14 @@
 	err = clk_prepare_enable(s->clk);
 	if (err) {
 		dev_err(s->dev, "Failed to enable clk!\n");
-		return err;
+		goto disable_clk_ahb;
 	}
 
 	return 0;
+
+disable_clk_ahb:
+	clk_disable_unprepare(s->clk_ahb);
+	return err;
 }
 
 /*