message: update TpuDualNet comment
diff: @@ -31,10 +31,14 @@ namespace minigo {
  class TpuDualNet : public DualNet {
  public:
  + // buffer_count: How many buffers to use for batched inference, i.e. the
  + // number of inference requests the model batcher will send in parallel.
  + // Reasonable choices are even integers in the range [2, 10].
  // tpu_name: The gRPC address of the VM's TPU, e.g. "grpc://10.240.2.10:8470".
  // graph_path: A frozen GraphDef proto suitable for running on TPU, e.g.
  // generated by freeze_graph.py --use_tpu
  - TpuDualNet(int buffer_count, const std::string& tpu_name, const std::string& graph_path);
  + TpuDualNet(int buffer_count, const std::string& tpu_name,
  + const std::string& graph_path);
  ~TpuDualNet() override;
  void RunMany(std::vector<const BoardFeatures*> features,
  