!15104 [MS][LITE]prepare data when getting inputs

From: @zhaizhiqiang
Reviewed-by: @zhang_xue_tong,@hangangqiang
Signed-off-by: @zhang_xue_tong

mindspore/lite/src/cxx_api/model/model_impl.cc

@@ -213,6 +213,7 @@ std::vector<MSTensor> ModelImpl::GetInputs() {
   }
   res.resize(inputs.size());
   for (size_t i = 0; i < inputs.size(); i++) {
+    inputs[i]->MutableData();  // prepare data
     auto impl = std::shared_ptr<MSTensor::Impl>(new (std::nothrow) MSTensor::Impl(inputs[i]));
     if (impl == nullptr || impl->lite_tensor() == nullptr) {
       MS_LOG(ERROR) << "Create tensor failed.";

mindspore/lite/tools/benchmark/benchmark.cc

@@ -410,6 +410,10 @@ int Benchmark::MarkPerformance() {
   uint64_t time_avg = 0;
 
   for (int i = 0; i < flags_->loop_count_; i++) {
+    auto inputs = session_->GetInputs();
+    for (auto tensor : inputs) {
+      tensor->MutableData();  // prepare data
+    }
     session_->BindThread(true);
     auto start = GetTimeUs();
     auto status = session_->RunGraph(before_call_back_, after_call_back_);