message: fix of tensor liveness issue
diff: @@ -517,6 +517,9 @@ class NGraphEncapsulateOp : public OpKernel {
  private:
  Graph m_graph;
  + static std::weak_ptr<ng::runtime::Backend> s_ng_backend_wptr;
  + std::shared_ptr<ng::runtime::Backend> m_ng_backend
  + GUARDED_BY(s_ng_backend_mutex);
  std::unordered_map<std::string, std::shared_ptr<ngraph::Function>>
  m_ng_functions;
  NgFunctionIOCache m_ng_function_input_cache_map;
  @@ -525,9 +528,6 @@ class NGraphEncapsulateOp : public OpKernel {
  int m_ngraph_cluster;
  std::vector<bool> m_input_is_static;
  - static std::weak_ptr<ng::runtime::Backend> s_ng_backend_wptr;
  - std::shared_ptr<ng::runtime::Backend> m_ng_backend
  - GUARDED_BY(s_ng_backend_mutex);
  static std::string s_ng_backend_name;
  static mutex s_ng_backend_mutex;
  };
  