rtc: rtc-r9701: 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-r9701.c

@@ -154,8 +154,8 @@ static int r9701_probe(struct spi_device *spi)
 		}
 	}
 
-	rtc = rtc_device_register("r9701",
-				&spi->dev, &r9701_rtc_ops, THIS_MODULE);
+	rtc = devm_rtc_device_register(&spi->dev, "r9701",
+				&r9701_rtc_ops, THIS_MODULE);
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);
 
@@ -166,9 +166,6 @@ static int r9701_probe(struct spi_device *spi)
 
 static int r9701_remove(struct spi_device *spi)
 {
-	struct rtc_device *rtc = dev_get_drvdata(&spi->dev);
-
-	rtc_device_unregister(rtc);
 	return 0;
 }