fix: Correct error variable pointer in Sagemaker server (#8608)

Author: yinggeh

src/sagemaker_server.cc

@@ -1,4 +1,4 @@
-// Copyright 2021-2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// Copyright 2021-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
@@ -735,7 +735,7 @@ SagemakerAPIServer::SageMakerMMEUnloadModel(
       server_.get(), repo_parent_path.c_str());
 
   if (unregister_err != nullptr) {
-    EVBufferAddErrorJson(req->buffer_out, unload_err);
+    EVBufferAddErrorJson(req->buffer_out, unregister_err);
     evhtp_send_reply(req, EVHTP_RES_BADREQ);
     LOG_ERROR << "Unable to unregister model repository for path: "
               << repo_parent_path << std::endl;