Add not to a command that is expected to fail.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187065 91177308-0d34-0410-b5e6-96231b3b80d8

test/Preprocessor/macro_with_initializer_list.cpp

 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
-// RUN: %clang_cc1 -std=c++11 -fsyntax-only -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
+// RUN: not %clang_cc1 -std=c++11 -fsyntax-only -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
 namespace std {
   template <class X>
   class initializer_list {