rtc: omap: fix error path when pinctrl_register fails

If pinctrl_register() fails probe will return with an error without locking
the RTC and disabling pm_runtime.
Set ret and jump to err instead.

Fixes: 97ea1906b3c2 ("rtc: omap: Support ext_wakeup configuration")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 13f7cd1..3bdc041 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -830,7 +830,8 @@ static int omap_rtc_probe(struct platform_device *pdev)
 	rtc->pctldev = pinctrl_register(&rtc_pinctrl_desc, &pdev->dev, rtc);
 	if (IS_ERR(rtc->pctldev)) {
 		dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
-		return PTR_ERR(rtc->pctldev);
+		ret = PTR_ERR(rtc->pctldev);
+		goto err;
 	}
 
 	return 0;