HID: use kobj_to_dev()

Use kobj_to_dev() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-roccat-kone.c b/drivers/hid/hid-roccat-kone.c
index c292650..bf4675a 100644
--- a/drivers/hid/hid-roccat-kone.c
+++ b/drivers/hid/hid-roccat-kone.c
@@ -269,8 +269,7 @@
 static ssize_t kone_sysfs_read_settings(struct file *fp, struct kobject *kobj,
 		struct bin_attribute *attr, char *buf,
 		loff_t off, size_t count) {
-	struct device *dev =
-			container_of(kobj, struct device, kobj)->parent->parent;
+	struct device *dev = kobj_to_dev(kobj)->parent->parent;
 	struct kone_device *kone = hid_get_drvdata(dev_get_drvdata(dev));
 
 	if (off >= sizeof(struct kone_settings))
@@ -294,8 +293,7 @@
 static ssize_t kone_sysfs_write_settings(struct file *fp, struct kobject *kobj,
 		struct bin_attribute *attr, char *buf,
 		loff_t off, size_t count) {
-	struct device *dev =
-			container_of(kobj, struct device, kobj)->parent->parent;
+	struct device *dev = kobj_to_dev(kobj)->parent->parent;
 	struct kone_device *kone = hid_get_drvdata(dev_get_drvdata(dev));
 	struct usb_device *usb_dev = interface_to_usbdev(to_usb_interface(dev));
 	int retval = 0, difference, old_profile;
@@ -332,8 +330,7 @@
 static ssize_t kone_sysfs_read_profilex(struct file *fp,
 		struct kobject *kobj, struct bin_attribute *attr,
 		char *buf, loff_t off, size_t count) {
-	struct device *dev =
-			container_of(kobj, struct device, kobj)->parent->parent;
+	struct device *dev = kobj_to_dev(kobj)->parent->parent;
 	struct kone_device *kone = hid_get_drvdata(dev_get_drvdata(dev));
 
 	if (off >= sizeof(struct kone_profile))
@@ -353,8 +350,7 @@
 static ssize_t kone_sysfs_write_profilex(struct file *fp,
 		struct kobject *kobj, struct bin_attribute *attr,
 		char *buf, loff_t off, size_t count) {
-	struct device *dev =
-			container_of(kobj, struct device, kobj)->parent->parent;
+	struct device *dev = kobj_to_dev(kobj)->parent->parent;
 	struct kone_device *kone = hid_get_drvdata(dev_get_drvdata(dev));
 	struct usb_device *usb_dev = interface_to_usbdev(to_usb_interface(dev));
 	struct kone_profile *profile;