Bluetooth: btusb: Fix error return code in btusb_mtk_setup_firmware()

Fix to return error code -EINVAL from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: a1c49c43 ("Bluetooth: btusb: Add protocol support for MediaTek MT7668U USB devices")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btusb.c

@@ -2762,8 +2762,10 @@ static int btusb_mtk_setup_firmware(struct hci_dev *hdev, const char *fwname)
 	fw_size = fw->size;
 
 	/* The size of patch header is 30 bytes, should be skip */
-	if (fw_size < 30)
+	if (fw_size < 30) {
+		err = -EINVAL;
 		goto err_release_fw;
+	}
 
 	fw_size -= 30;
 	fw_ptr += 30;