message: Remove dangling comma from device string
  Reviewers: #tensorflow, hakons
diff: @@ -173,7 +173,7 @@ Service::Service(const ServiceOptions& options,
  for (int i = 0; i < execute_backend_->device_count(); ++i) {
  se::StreamExecutor* executor = stream_executors.at(i);
  const auto& description = executor->GetDeviceDescription();
  - LOG(INFO) << StrFormat(" StreamExecutor device (%d): %s, %s", i,
  + LOG(INFO) << StrFormat(" StreamExecutor device (%d): %s %s", i,
  description.name(),
  description.platform_version());
  }
  