Bluetooth: btusb: Free driver data on USB shutdown

Instead of using the hci-destruct callback we free our private driver
data on USB shutdown. We already called hci_unregister_dev() here so the
hci core will never ever call our callbacks again except the destruct
callback.

However, there is no reason to keep our *private* driver data alive if
we get never called again and the hci-core does never touch it the data.
So we simply free it right away and set the destruct callback to NULL.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

drivers/bluetooth/btusb.c

@@ -783,15 +783,6 @@ static int btusb_send_frame(struct sk_buff *skb)
 	return err;
 }
 
-static void btusb_destruct(struct hci_dev *hdev)
-{
-	struct btusb_data *data = hdev->driver_data;
-
-	BT_DBG("%s", hdev->name);
-
-	kfree(data);
-}
-
 static void btusb_notify(struct hci_dev *hdev, unsigned int evt)
 {
 	struct btusb_data *data = hdev->driver_data;
@@ -1004,7 +995,6 @@ static int btusb_probe(struct usb_interface *intf,
 	hdev->close    = btusb_close;
 	hdev->flush    = btusb_flush;
 	hdev->send     = btusb_send_frame;
-	hdev->destruct = btusb_destruct;
 	hdev->notify   = btusb_notify;
 
 	hdev->owner = THIS_MODULE;
@@ -1108,6 +1098,7 @@ static void btusb_disconnect(struct usb_interface *intf)
 	__hci_dev_put(hdev);
 
 	hci_free_dev(hdev);
+	kfree(data);
 }
 
 #ifdef CONFIG_PM