HID: usbhid: Make hid_is_usb() non-inline

By making hid_is_usb() a non-inline function the lowlevel usbhid driver
does not have to be exported anymore.

Also mark the argument as const as it is not modified.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Rheinsberg <david.rheinsberg@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/usbhid/hid-core.c

@@ -1334,6 +1334,12 @@ struct hid_ll_driver usb_hid_driver = {
 };
 EXPORT_SYMBOL_GPL(usb_hid_driver);
 
+bool hid_is_usb(const struct hid_device *hdev)
+{
+	return hdev->ll_driver == &usb_hid_driver;
+}
+EXPORT_SYMBOL_GPL(hid_is_usb);
+
 static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
 	struct usb_host_interface *interface = intf->cur_altsetting;

include/linux/hid.h

@@ -866,10 +866,7 @@ static inline bool hid_is_using_ll_driver(struct hid_device *hdev,
 	return hdev->ll_driver == driver;
 }
 
-static inline bool hid_is_usb(struct hid_device *hdev)
-{
-	return hid_is_using_ll_driver(hdev, &usb_hid_driver);
-}
+extern bool hid_is_usb(const struct hid_device *hdev);
 
 #define	PM_HINT_FULLON	1<<5
 #define PM_HINT_NORMAL	1<<1