header-checker: Re-use GetODRListMapKey

Bug: 74764811
Test: ./tests/test.py
Change-Id: Idb524a7e783c65aee08875bc1cec2481c06e880a
diff --git a/vndk/tools/header-checker/src/repr/ir_representation.cpp b/vndk/tools/header-checker/src/repr/ir_representation.cpp
index e755002..50d1bf9 100644
--- a/vndk/tools/header-checker/src/repr/ir_representation.cpp
+++ b/vndk/tools/header-checker/src/repr/ir_representation.cpp
@@ -130,8 +130,8 @@
   }
   auto it = AddToMapAndTypeGraph(
       std::move(enum_type), &enum_types_, &type_graph_);
-  AddToODRListMap(it->second.GetUniqueId() + it->second.GetSourceFile(),
-                  (&it->second));
+  const std::string &key = GetODRListMapKey(&(it->second));
+  AddToODRListMap(key, (&it->second));
 }