message: Fix unused-result warning
diff: @@ -223,7 +223,7 @@ void bootstrap(actor_system& system, const string& wdir,
  #define RETURN_WITH_ERROR(output) \
  do { \
  ::std::cerr << output << ::std::endl; \
  - return 1; \
  + return EXIT_FAILURE; \
  } while (true)
  namespace {
  @@ -242,9 +242,12 @@ struct config : actor_system_config {
  int main(int argc, char** argv) {
  config cfg;
  - cfg.parse(argc, argv);
  + if (auto err = cfg.parse(argc, argv)) {
  + std::cerr << "error parsing command line: " << to_string(err) << '\n';
  + return EXIT_FAILURE;
  + }
  if (cfg.cli_helptext_printed)
  - return 0;
  + return EXIT_SUCCESS;
  if (cfg.slave_mode)
  RETURN_WITH_ERROR("cannot use slave mode in caf-run tool");
  std::unique_ptr<char, void (*)(void*)> pwd{getcwd(nullptr, 0), ::free};
  @@ -265,4 +268,5 @@ int main(int argc, char** argv) {
  hosts.erase(hosts.begin());
  bootstrap(system, (cfg.wdir.empty()) ? pwd.get() : cfg.wdir.c_str(), master,
  std::move(hosts), cmd, xs);
  + return EXIT_SUCCESS;
  }
  