[NaCl SDK] Consistent use of copyright header.

native_client_sdk/src/libraries/nacl_io/nacl_io.cc

-/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
 
 #include "nacl_io/nacl_io.h"
 
 #include <stdlib.h>
 #include "nacl_io/kernel_intercept.h"
 
 void nacl_io_init() {
   ki_init(NULL);
 }
 
 void nacl_io_init_ppapi(PP_Instance instance,
                         PPB_GetInterface get_interface) {
   ki_init_ppapi(NULL, instance, get_interface);
 }