power-supply: use kobj_to_dev()

Use kobj_to_dev() instead of open-coding it

Signed-off-by: Jian Dong <dongjian@yulong.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/ds2760_battery.c

@@ -198,7 +198,7 @@ static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
 			     struct bin_attribute *bin_attr, char *buf,
 			     loff_t off, size_t count)
 {
-	struct device *dev = container_of(kobj, struct device, kobj);
+	struct device *dev = kobj_to_dev(kobj);
 	return w1_ds2760_read(dev, buf, off, count);
 }