mac/rlz: Correctly check for fd existence

rlz/mac/lib/rlz_value_store_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "rlz/mac/lib/rlz_value_store_mac.h"
 
 #include "base/eintr_wrapper.h"
 #include "base/mac/foundation_util.h"
 #include "base/file_path.h"
 #include "base/logging.h"
@@ skipping 278 matching lines @@
       file_lock_ = -1;
       return false;
     }
     return true;
   } else {
     return file_lock_ != -1;
   }
 }
 
 void RecursiveCrossProcessLock::ReleaseLock() {
-  if (file_lock_) {
+  if (file_lock_ != -1) {
     ignore_result(HANDLE_EINTR(flock(file_lock_, LOCK_UN)));
     ignore_result(HANDLE_EINTR(close(file_lock_)));
     file_lock_ = -1;
   }
 
   locking_thread_ = 0;
   pthread_mutex_unlock(&recursive_lock_);
 }
 
 
@@ skipping 135 matching lines @@
   } else {
     // Not Unsafe on OS X.
     g_test_folder =
       [[NSString alloc] initWithUTF8String:directory.AsUTF8Unsafe().c_str()];
   }
 }
 
 }  // namespace testing
 
 }  // namespace rlz_lib