drivers/rtc/class.c: fix device_register() error handling

If device_register() fails then call put_device().  See comment to
device_register.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/class.c

@@ -158,8 +158,10 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev,
 	rtc_dev_prepare(rtc);
 
 	err = device_register(&rtc->dev);
-	if (err)
+	if (err) {
+		put_device(&rtc->dev);
 		goto exit_kfree;
+	}
 
 	rtc_dev_add_device(rtc);
 	rtc_sysfs_add_device(rtc);