Fix error introduced when renaming variable in test_suite.dart, in r4671.

tools/testing/dart/test_suite.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Classes and methods for enumerating and preparing tests.
  *
  * This library includes:
  *
  * - Creating tests by listing all the Dart files in certain directories,
@@ skipping 712 matching lines @@
     List<String> dartOptions = optionsFromFile["dartOptions"];
     List<List<String>> vmOptionsList = optionsFromFile["vmOptions"];
     Expect.isTrue(!isMultitest || dartOptions == null);
     if (dartOptions == null) {
       args.add(filename);
     } else {
       var executable_name = dartOptions[0];
       // TODO(ager): Get rid of this hack when the runtime checkout goes away.
       var file = new File(executable_name);
       if (!file.existsSync()) {
-        executable_name = '../$filename';
+        executable_name = '../$executable_name';
         Expect.isTrue(new File(executable_name).existsSync());
         dartOptions[0] = executable_name;
       }
       args.addAll(dartOptions);
     }
 
     var result = new List<List<String>>();
     Expect.isFalse(vmOptionsList.isEmpty(), "empty vmOptionsList");
     for (var vmOptions in vmOptionsList) {
       var options = new List<String>.from(vmOptions);
@@ skipping 398 matching lines @@
  * $noCrash tests are expected to be flaky but not crash
  * $pass tests are expected to pass
  * $failOk tests are expected to fail that we won't fix
  * $fail tests are expected to fail that we should fix
  * $crash tests are expected to crash that we should fix
  * $timeout tests are allowed to timeout
 """;
     print(report);
    }
 }