rtc: rtc-ab3100: use devm_rtc_device_register()

devm_rtc_device_register() is device managed and makes cleanup paths
simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-ab3100.c b/drivers/rtc/rtc-ab3100.c
index c2f12d3..47a4f2c4 100644
--- a/drivers/rtc/rtc-ab3100.c
+++ b/drivers/rtc/rtc-ab3100.c
@@ -229,8 +229,8 @@
 		/* Ignore any error on this write */
 	}
 
-	rtc = rtc_device_register("ab3100-rtc", &pdev->dev, &ab3100_rtc_ops,
-				  THIS_MODULE);
+	rtc = devm_rtc_device_register(&pdev->dev, "ab3100-rtc",
+					&ab3100_rtc_ops, THIS_MODULE);
 	if (IS_ERR(rtc)) {
 		err = PTR_ERR(rtc);
 		return err;
@@ -242,9 +242,6 @@
 
 static int __exit ab3100_rtc_remove(struct platform_device *pdev)
 {
-	struct rtc_device *rtc = platform_get_drvdata(pdev);
-
-	rtc_device_unregister(rtc);
 	platform_set_drvdata(pdev, NULL);
 	return 0;
 }