rtc: rtc-da9055: 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>

drivers/rtc/rtc-da9055.c

@@ -294,7 +294,7 @@ static int da9055_rtc_probe(struct platform_device *pdev)
 
 	device_init_wakeup(&pdev->dev, 1);
 
-	rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
+	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 					&da9055_rtc_ops, THIS_MODULE);
 	if (IS_ERR(rtc->rtc)) {
 		ret = PTR_ERR(rtc->rtc);
@@ -317,9 +317,6 @@ static int da9055_rtc_probe(struct platform_device *pdev)
 
 static int da9055_rtc_remove(struct platform_device *pdev)
 {
-	struct da9055_rtc *rtc = pdev->dev.platform_data;
-
-	rtc_device_unregister(rtc->rtc);
 	platform_set_drvdata(pdev, NULL);
 
 	return 0;