Change printf invocation to use format statement.

utility/sign_image.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.
  *
  * Utility for signing boot firmware images.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 #include "file_keys.h"
 #include "utility.h"
 #include "host_key.h"
 #include "host_signature.h"
 #include "host_common.h"
 
 static void usage()
 {
   static char* help_mesg =
       "Usage: sign_image <fw_version> <fw_key_block> <signing_key> "
       "<kernel_public_key> <firmware_file> <output_file>\n";
-  printf(help_mesg);
+  printf("%s", help_mesg);
 }
 
 int SignAndWriteImage(uint64_t fw_version, VbKeyBlockHeader* wrapper_kb,
                       VbPrivateKey* signing_key,
                       VbPublicKey* nested_pubkey,
                       uint8_t* image, uint64_t image_size,
                       FILE* out_file)
 {
   VbFirmwarePreambleHeader* fw_preamble = NULL;
   int rv = 1;
@@ skipping 72 matching lines @@
 
   rv = SignAndWriteImage(version, firmware_kb, signing_key,
                          kernel_pubk, firmware, fw_size, out_file);
 
   fclose(out_file);
   if (rv) {
     unlink(argv[6]);
   }
   return rv;
 }