Fix variable name

Author: dyastremsky

src/libtorch.cc

@@ -1884,7 +1884,7 @@ ModelInstanceState::SetInputTensors(
       const auto torch_dtype =
           ConvertDataTypeToTorchType(batch_input.DataType());
       torch::TensorOptions options{torch_dtype.second};
-      auto updated_options = (memory_type == TRITONSERVER_MEMORY_GPU)
+      auto updated_options = (dst_memory_type == TRITONSERVER_MEMORY_GPU)
                                ? options.device(torch::kCUDA, device_.index())
                                : options.device(torch::kCPU);