Use ListInstance typedef in more places

Change-Id: Ic41218a1e09f76d7455816163d9b3ca24b0b94ca
diff --git a/src/ast_path.cpp b/src/ast_path.cpp
index f7c0022..b913d0c 100644
--- a/src/ast_path.cpp
+++ b/src/ast_path.cpp
@@ -96,7 +96,7 @@
     return this->m_name == b.m_name;
 }
 
-listElement_::listElement_(const std::string& listName, const std::map<std::string, leaf_data_>& keys)
+listElement_::listElement_(const std::string& listName, const ListInstance& keys)
     : m_name(listName)
     , m_keys(keys)
 {