Fix inconsistent license headers

highwayhash_arm64.go

@@ -1,20 +1,8 @@
 //+build !noasm
 
-/*
- * Minio Cloud Storage, (C) 2017 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright (c) 2017 Minio Inc. All rights reserved.
+// Use of this source code is governed by a license that can be
+// found in the LICENSE file.
 
 package highwayhash