!7979 fix memory leak

Merge pull request !7979 from zhaozhenlong/lite/issue/arithmetic_parameter_free_if_needed

mindspore/lite/src/runtime/kernel/arm/fp16/arithmetic_fp16.cc

@@ -107,7 +107,16 @@ int ArithmeticFP16CPUKernel::PreProcess() {
       MS_LOG(ERROR) << "InferShape fail!";
       return ret;
     }
-    param_ = reinterpret_cast<ArithmeticParameter *>(PopulateArithmetic(primitive_));
+    if (op_parameter_ != nullptr) {
+      free(op_parameter_);
+      op_parameter_ = nullptr;
+    }
+    op_parameter_ = PopulateArithmetic(primitive_);
+    if (op_parameter_ == nullptr) {
+      MS_LOG(ERROR) << "Malloc parameter failed";
+      return RET_ERROR;
+    }
+    param_ = reinterpret_cast<ArithmeticParameter *>(op_parameter_);
     ret = ReSize();
     if (ret != 0) {
       MS_LOG(ERROR) << "ReSize fail!ret: " << ret;

mindspore/lite/src/runtime/kernel/arm/fp32/arithmetic.cc

@@ -48,7 +48,16 @@ int ArithmeticCPUKernel::PreProcess() {
       MS_LOG(ERROR) << "InferShape fail!";
       return ret;
     }
-    arithmeticParameter_ = reinterpret_cast<ArithmeticParameter *>(PopulateArithmetic(primitive_));
+    if (op_parameter_ != nullptr) {
+      free(op_parameter_);
+      op_parameter_ = nullptr;
+    }
+    op_parameter_ = PopulateArithmetic(primitive_);
+    if (op_parameter_ == nullptr) {
+      MS_LOG(ERROR) << "Malloc parameter failed";
+      return RET_ERROR;
+    }
+    arithmeticParameter_ = reinterpret_cast<ArithmeticParameter *>(op_parameter_);
     ret = ReSize();
     if (ret != 0) {
       MS_LOG(ERROR) << "ReSize fail!ret: " << ret;