Fix a typo in the RSA benchmark.

src/platform/vboot_reference/utils/file_keys.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 functions for file and key handling.
  */
 
 #include "file_keys.h"
 
 #include <fcntl.h>
@@ skipping 33 matching lines @@
     fprintf(stderr, "Couldn't read key into a buffer.\n");
     return NULL;
   }
 
   close(fd);
   return buf;
 }
 
 RSAPublicKey* RSAPublicKeyFromFile(const char* input_file) {
   uint32_t len;
-  RSAPublicKey* key;
+  RSAPublicKey* key = NULL;
   uint8_t* buf = BufferFromFile(input_file, &len);
   if (buf)
     key = RSAPublicKeyFromBuf(buf, len);
   Free(buf);
   return key;
 }
 
 uint8_t* SignatureFile(const char* input_file, const char* key_file,
                        int algorithm) {
   char* sign_utility = "./sign_data.sh";
@@ skipping 25 matching lines @@
   if (fread(signature, signature_size, 1, cmd_out) != 1) {
     fprintf(stderr, "Couldn't read signature.\n");
     pclose(cmd_out);
     Free(signature);
     return NULL;
   }
 
   pclose(cmd_out);
   return signature;
 }