HID: switch to using input_dev->dev.parent

In preparation for struct class_device -> struct device input
core conversion switch to using input_dev->dev.parent when
specifying device position in sysfs tree.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/usbhid/hid-plff.c b/drivers/hid/usbhid/hid-plff.c
index 76d2e6e..d6a8f2b 100644
--- a/drivers/hid/usbhid/hid-plff.c
+++ b/drivers/hid/usbhid/hid-plff.c
@@ -37,7 +37,7 @@
 static int hid_plff_play(struct input_dev *dev, void *data,
 			 struct ff_effect *effect)
 {
-	struct hid_device *hid = dev->private;
+	struct hid_device *hid = input_get_drvdata(dev);
 	struct plff_device *plff = data;
 	int left, right;