Initialized variable to fix -Wmaybe-uninitialized warning.

net/third_party/mozilla_security_manager/nsPKCS12Blob.cpp

 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (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.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
@@ skipping 415 matching lines @@
     // token may ignore this attribute (and hence still be able to export) but
     // we still refuse to attempt an export.
     // In addition, some tokens may not support this attribute, in which case
     // we still attempt the export and let the token implementation dictate
     // the export behavior.
     if (nssCert->slot) {
       SECKEYPrivateKey *privKey=PK11_FindKeyByDERCert(nssCert->slot,
                                                       nssCert,
                                                       NULL);  // wincx
        if (privKey) {
-        PRBool privKeyIsExtractable;
+        PRBool privKeyIsExtractable = PR_FALSE;
         SECStatus rv = isExtractable(privKey, &privKeyIsExtractable);
         SECKEY_DestroyPrivateKey(privKey);
 
         if (rv == SECSuccess && !privKeyIsExtractable) {
           LOG(ERROR) << "Private key is not extractable";
           continue;
         }
       }
     }
 
@@ skipping 30 matching lines @@
 finish:
   if (srv)
     LOG(ERROR) << "PKCS#12 export failed with error " << PORT_GetError();
   if (ecx)
     SEC_PKCS12DestroyExportContext(ecx);
   SECITEM_ZfreeItem(&unicodePw, PR_FALSE);
   return return_count;
 }
 
 }  // namespace mozilla_security_manager