Fix op_tester attribute error format mismatch (PaddlePaddle#79181)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: SigureMo <sigure.qaq@gmail.com>

Author: 3 people

test/cpp/fluid/benchmark/op_tester.cc

@@ -221,7 +221,7 @@ void OpTester::CreateOpDesc() {
         attr_types.find(name),
         attr_types.end(),
         common::errors::NotFound(
-            "Operator %s does not have attribute %d.", type_, name));
+            "Operator %s does not have attribute %s.", type_, name));
 
     const std::string &value_str = item.second;
     const framework::proto::AttrType &type = attr_types[name];