Bluetooth: btusb: Remove redundant call to btusb_free_frags()

The btusb_disconnect() callback calls hci_unregister_dev() which in turn
calls btusb_close() if the HCI device is powered. The btusb_close()
function in turn will call btusb_free_frags(). It's therefore
unnecessary to have another call to btusb_free_frags() in the
btusb_disconnect() function. Besides the redundancy the second call
seems to also cause some strange stability issues which this patch then
also fixes.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btusb.c

@@ -2767,7 +2767,6 @@ static void btusb_disconnect(struct usb_interface *intf)
 	else if (data->isoc)
 		usb_driver_release_interface(&btusb_driver, data->isoc);
 
-	btusb_free_frags(data);
 	hci_free_dev(hdev);
 }