Cleanup

util.ml

@@ -218,8 +218,7 @@ let rec traverse u ( *: ) trav node =
   | _ -> (node, u)
 
 let traverse_unit visit node =
-  let (node, _) = traverse () (fun () () -> ()) (fun n -> (visit n, ())) node in
-  node
+  fst (traverse () (fun () () -> ()) (fun n -> (visit n, ())) node)
 
 let traverse_list visit = traverse [] (@) visit