IdentityBuilder should add Delimit for each input (#14592)

…("####") should append for each input_def, not only on the last one
else branch of this if should return ignore_identity

3d7518762a/onnxruntime/core/optimizer/identical_children_consolidation.cc (L66)
identity.append("####") should append for each input_def, not only on
the last one
### Description
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### Motivation and Context
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onnxruntime/core/optimizer/identical_children_consolidation.cc

@@ -117,8 +117,11 @@ string_view IdenticalChildrenConsolidation::IdentityBuilder(const Graph& graph,
       } else {
         identity.append(name);
       }
+    } else {
+      return ignore_identity;
     }
+    identity.append("####");
   }
-  return {identity.append("####")};
+  return {identity};
 }
 }  // namespace onnxruntime