!15894 Modify MaximumGrad op

From: @ZhengQihao3f3f3f
Reviewed-by: @wuxuejian,@liangchenghui
Signed-off-by: @wuxuejian

mindspore/ccsrc/backend/kernel_compiler/cpu/maximum_grad_cpu_kernel.cc

@@ -113,8 +113,10 @@ void MaximumGradCPUKernel::LaunchKernel(const std::vector<AddressPtr> &inputs, c
 
   size_t x_tensor_len = GetTensorLen(x_shape_);
   size_t y_tensor_len = GetTensorLen(y_shape_);
-  memset(dx_addr, 0, x_tensor_len * sizeof(T));
-  memset(dy_addr, 0, y_tensor_len * sizeof(T));
+  size_t x_tensor_size = x_tensor_len * sizeof(T);
+  size_t y_tensor_size = y_tensor_len * sizeof(T);
+  memset_s(dx_addr, x_tensor_size, 0, x_tensor_size);
+  memset_s(dy_addr, y_tensor_size, 0, y_tensor_size);
 
   std::vector<size_t> x_shape(dout_shape.size(), 1);
   std::vector<size_t> y_shape(dout_shape.size(), 1);