message: Add parenthesis to fix warning
diff: @@ -279,7 +279,7 @@ bool FileSystem::ListFiles(const string &directory, function<void(string, bool)>
  }
  struct stat status;
  stat(full_path.c_str(), &status);
  - if (!status.st_mode & S_IFREG && !status.st_mode & S_IFDIR) {
  + if (!(status.st_mode & S_IFREG) && !(status.st_mode & S_IFDIR)) {
  // not a file or directory: skip
  continue;
  }
  