Make vboot_reference build in MSVC command line environment.

tests/sha_tests.c

 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* FIPS 180-2 Tests for message digest functions. */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 60 matching lines @@
       fprintf(stderr, "Test vector %d PASSED for SHA-512\n", i+1);
     }
     else {
       fprintf(stderr, "Test vector %d FAILED for SHA-512\n", i+1);
       success = 0;
     }
   }
   return success;
 }
 
+/* disable MSVC warnings on unused arguments */
+__pragma(warning (disable: 4100))
+
 int main(int argc, char* argv[]) {
   int success = 1;
   /* Initialize long_msg with 'a' x 1,000,000 */
   long_msg = (char *) malloc(1000001);
   memset(long_msg, 'a', 1000000);
   long_msg[1000000]=0;
 
   if (!SHA1_tests())
     success = 0;
   if (!SHA256_tests())
     success = 0;
   if (!SHA512_tests())
     success = 0;
 
   free(long_msg);
 
   return !success;
 }