title: SecCopyErrorMessageString gives "Use of unresolved identifier" in swift
body: <p>Trying to use SecCopyErrorMessageString to interpret errorCode.  in swift :</p>
  
  <pre><code>    var result: OSStatus
      result = SecItemAdd(query as CFDictionary, nil);
  
  
      if result != errSecSuccess {
      let errorDescription = SecCopyErrorMessageString(result,nil)
     //     NSLog("Keychain Error: %@", errorDescription)
  </code></pre>
  
  <p>The error of "Unresolved identifier" starts from "SecCopyError..."</p>