fix ernie serialize problem (#36769)

paddle/fluid/inference/tensorrt/engine.cc

@@ -233,11 +233,11 @@ void TensorRTEngine::FreezeNetwork() {
       *network(), *infer_builder_config_));
 #else
   infer_builder_config_->setFlag(nvinfer1::BuilderFlag::kSPARSE_WEIGHTS);
-  infer_ptr<nvinfer1::IHostMemory> plan(infer_builder_->buildSerializedNetwork(
+  ihost_memory_.reset(infer_builder_->buildSerializedNetwork(
       *network(), *infer_builder_config_));
   infer_ptr<nvinfer1::IRuntime> runtime(createInferRuntime(&logger_));
-  infer_engine_.reset(
-      runtime->deserializeCudaEngine(plan->data(), plan->size()));
+  infer_engine_.reset(runtime->deserializeCudaEngine(ihost_memory_->data(),
+                                                     ihost_memory_->size()));
 #endif
 
   PADDLE_ENFORCE_NOT_NULL(

paddle/fluid/inference/tensorrt/engine.h

@@ -273,7 +273,14 @@ class TensorRTEngine {
         infer_engine_,
         platform::errors::InvalidArgument(
             "The TensorRT engine must be built first before serialization"));
+#if IS_TRT_VERSION_LT(8000)
     ihost_memory_.reset(infer_engine_->serialize());
+#else
+    PADDLE_ENFORCE_NOT_NULL(
+        ihost_memory_,
+        platform::errors::InvalidArgument(
+            "TensorRT >= 8.0 requires that buildSerializedNetwork is called"));
+#endif
     return ihost_memory_.get();
   }