HID: letsketch: Use hid_is_usb()

Don't open code existing functionality.

Signed-off-by: Thomas Weißschuh <[e-mail]>
Reviewed-by: David Rheinsberg <[e-mail]>
Reviewed-by: Hans de Goede <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>

drivers/hid/hid-letsketch.c

···
 	char buf[256];
 	int i, ret;
 
-	if (!hid_is_using_ll_driver(hdev, &usb_hid_driver))
+	if (!hid_is_usb(hdev))
 		return -ENODEV;
 
 	intf = to_usb_interface(hdev->dev.parent);