Copy outputs only if the use is outside the sub-graph (#3446)

* Copy outputs only if the use is outside the sub-graph

* Use unordered_set find

src/contrib/mlir/pass/mlir_subgraph_extraction.cpp

@@ -257,7 +257,10 @@ bool MLIRSubgraphExtractionPass::run_on_function(std::shared_ptr<Function> func)
 
             for (descriptor::Input* in_desc : input_descs)
             {
-                in_desc->replace_output(ck, i);
+                if (nodes.find(in_desc->get_node()) == nodes.end())
+                {
+                    in_desc->replace_output(ck, i);
+                }
             }
         }
     }