Fix typo in fix.

pkg/async/test/result_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import "dart:async";
 import "dart:collection";
 import "package:async/result.dart";
 import "package:unittest/unittest.dart";
 
 void main() {
@@ skipping 218 matching lines @@
     c.add(new Result.value(42));
     c.add(new Result.error("BAD", stack));
     c.add(new Result.value(37));
     c.close();
   });
 
 
   test("flatten error 1", () {
     Result<int> error = new Result<int>.error("BAD", stack);
     Result<int> flattened =
-        Result.flatten(new Result<Result<int>>.error(error));
+        Result.flatten(new Result<Result<int>>.error("BAD", stack));
     expectResult(flattened, error);
   });
 
   test("flatten error 2", () {
     Result<int> error = new Result<int>.error("BAD", stack);
     Result<Result<int>> result = new Result<Result<int>>.value(error);
     Result<int> flattened = Result.flatten(result);
     expectResult(flattened, error);
   });
 
@@ skipping 27 matching lines @@
   void add(T value) { onData(value); }
   void addError(error, [StackTrace stack]) { onError(error, stack); }
   void close() { onDone(); }
 
   static void _nullData(value) { fail("Unexpected sink add: $value"); }
   static void _nullError(e, StackTrace s) {
     fail("Unexpected sink addError: $e");
   }
   static void _nullDone() { fail("Unepxected sink close"); }
 }