Test addlatexhash_test: fix missed renamed variable.

tests/standalone/io/addlatexhash_test.dart

 #!/usr/bin/env dart
 // Copyright (c) 2014, 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.
 
 // testing ../../../tools/addlatexhash.dart
 
 import 'dart:io';
 import 'package:path/path.dart' as path;
 import '../../../tools/addlatexhash.dart';
@@ skipping 139 matching lines @@
       Process.runSync("latex", [fileName], workingDirectory: workingDirectory);
 
   runAddHash() =>
       Process.runSync(dartExecutable,
                       [path.join(dartRootPath, "tools", "addlatexhash.dart"),
                        tmpSpecPath,
                        hashPath,
                        listPath]);
 
   runDvi2tty(dviFile) =>
-      Process.runSync("dvi2tty", [dviFile], workingDirectory: tmpDir.path);
+      Process.runSync("dvi2tty", [dviFile], workingDirectory: tmpDirPath);
 
   chkDvi2tty(file, subject) =>
       checkAction(runDvi2tty(file), "dvitty on $subject failed");
 
   // perform test
   var renewLMHashCmd = r"\renewcommand{\LMHash}[1]{\OriginalLMHash{xxxx}}";
   new File(styPath)
       .copySync(tmpStyPath)
       .writeAsStringSync(renewLMHashCmd, mode: FileMode.APPEND);
   new File(specPath).copySync(tmpSpecPath);
@@ skipping 24 matching lines @@
 main([args]) {
   testCutMatch();
   testSisp();
 
   runWithTempDir(testSameHash);
   // latex and dvi2tty are not installed in the standard test environment
   if (args.length > 0 && args[0] == "local") {
     runWithTempDir(testSameDVI);
   }
 }