!625 Fix check nullptr by calling function directly

Merge pull request !625 from JoyLvliang/fix-check-nullptr-by-calling-function

mindspore/ccsrc/session/session_basic.cc

@@ -572,7 +572,6 @@ KernelGraphPtr SessionBasic::ConstructKernelGraph(const AnfNodePtrList &lst, con
 // run graph steps
 void SessionBasic::LoadInputData(const std::shared_ptr<KernelGraph> &kernel_graph,
                                  const std::vector<tensor::TensorPtr> &inputs_const) const {
-  MS_EXCEPTION_IF_NULL(kernel_graph);
   std::vector<tensor::TensorPtr> inputs(inputs_const);
   size_t input_ctrl_size = 1;
   MS_EXCEPTION_IF_NULL(context_);
@@ -585,6 +584,8 @@ void SessionBasic::LoadInputData(const std::shared_ptr<KernelGraph> &kernel_grap
     MS_LOG(EXCEPTION) << "tensor input:" << inputs.size() << " is not equal graph inputs:" << input_nodes.size()
                       << ", input_ctrl_size:" << input_ctrl_size;
   }
+  auto ms_context = MsContext::GetInstance();
+  MS_EXCEPTION_IF_NULL(ms_context);
   for (size_t i = 0; i < inputs.size(); ++i) {
     auto tensor = inputs[i];
     MS_EXCEPTION_IF_NULL(tensor);
@@ -594,8 +595,7 @@ void SessionBasic::LoadInputData(const std::shared_ptr<KernelGraph> &kernel_grap
       auto pk_node = input_node->cast<ParameterPtr>();
       auto device_address = AnfAlgo::GetMutableOutputAddr(pk_node, 0);
       bool need_sync = false;
-      MS_EXCEPTION_IF_NULL(MsContext::GetInstance());
-      if (MsContext::GetInstance()->enable_pynative_infer()) {
+      if (ms_context->enable_pynative_infer()) {
         if (tensor->device_address().get() == nullptr || tensor->device_address() != device_address) {
           need_sync = true;
         }