!5451 remove parameter destruction in subgraph

Merge pull request !5451 from wandongdong/master

mindspore/lite/src/lite_kernel.h

@@ -74,7 +74,10 @@ class LiteKernel {
   }
 
   virtual ~LiteKernel() {
-    free(op_parameter_);
+    if (op_parameter_ != nullptr) {
+      free(op_parameter_);
+      op_parameter_ = nullptr;
+    }
   }
 
   virtual int Prepare();

mindspore/lite/src/runtime/kernel/opencl/subgraph_opencl_kernel.cc

@@ -261,26 +261,21 @@ int SubGraphOpenCLKernel::GetKernelFromToTensor(const std::vector<lite::tensor::
 }
 
 int SubGraphOpenCLKernel::UnInit() {
-  for (const auto tensor : in_convert_tensors_) {
+  for (const auto &tensor : in_convert_tensors_) {
     if (tensor != nullptr) {
       delete tensor;
     }
   }
-  for (const auto tensor : out_convert_tensors_) {
+  for (const auto &tensor : out_convert_tensors_) {
     if (tensor != nullptr) {
       delete tensor;
     }
   }
-  for (const auto op : in_convert_ops_) {
+  for (const auto &op : in_convert_ops_) {
     if (op != nullptr) {
       delete op;
     }
   }
-  for (const auto parameter : in_parameters_) {
-    if (parameter != nullptr) {
-      delete parameter;
-    }
-  }
   return RET_OK;
 }