rtc: rtc-88pm80x: 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-88pm80x.c

@@ -312,7 +312,7 @@ static int pm80x_rtc_probe(struct platform_device *pdev)
 	}
 	rtc_tm_to_time(&tm, &ticks);
 
-	info->rtc_dev = rtc_device_register("88pm80x-rtc", &pdev->dev,
+	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm80x-rtc",
 					    &pm80x_rtc_ops, THIS_MODULE);
 	if (IS_ERR(info->rtc_dev)) {
 		ret = PTR_ERR(info->rtc_dev);
@@ -346,7 +346,6 @@ static int pm80x_rtc_remove(struct platform_device *pdev)
 {
 	struct pm80x_rtc_info *info = platform_get_drvdata(pdev);
 	platform_set_drvdata(pdev, NULL);
-	rtc_device_unregister(info->rtc_dev);
 	pm80x_free_irq(info->chip, info->irq, info);
 	return 0;
 }