Remove the now unnecessary flag from test files

tests/language/parameter_initializer5_test.dart

 // Copyright (c) 2011, 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.
-//
-// DartOptions=--initializing-formal-access
-// VMOptions=--initializing-formal-access
 
 // Use the this.x parameter in an initializer expression.
 
 class Foo {
   var x, y;
   Foo(this.x): y = x { }
 }
 
 main() {
   new Foo(12);
 }