skip to query the attr 'is_test' in batch_norm op

test=develop

paddle/fluid/lite/operators/batch_norm_op.cc

@@ -82,7 +82,8 @@ bool BatchNormOp::AttachImpl(const cpp::OpDesc &op_desc, lite::Scope *scope) {
   param_.variance =
       scope->FindVar(op_desc.Input("Variance").front())->GetMutable<Tensor>();
   param_.y = scope->FindVar(op_desc.Output("Y").front())->GetMutable<Tensor>();
-  param_.is_test = op_desc.GetAttr<int>("is_test");
+  param_.is_test = true;  // TODO(hong19860320) param_.is_test =
+                          // op_desc.GetAttr<int>("is_test");
   param_.use_global_stats = op_desc.GetAttr<bool>("use_global_stats");
   if (!param_.is_test) {
     param_.mean_out =