Bluetooth: btusb: mediatek: Add err code to btusb claim iso printout

Add the error code to the message "Failed to claim iso
interface". That allows us to know which error case
usb_driver_claim_interface() hit.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

drivers/bluetooth/btusb.c

@@ -2688,7 +2688,7 @@ static void btusb_mtk_claim_iso_intf(struct btusb_data *data)
 	device_unlock(&btmtk_data->isopkt_intf->dev);
 	if (err < 0) {
 		btmtk_data->isopkt_intf = NULL;
-		bt_dev_err(data->hdev, "Failed to claim iso interface");
+		bt_dev_err(data->hdev, "Failed to claim iso interface: %d", err);
 		return;
 	}