fix typo in clang Makefile

[Mathieu Baudet]

All the more since one apparently needs to git-clean all git repos after the mistake :)

> On May 22, 2015, at 4:59 PM, Jonathan Roelofs <jonathan at codesourcery.com> wrote:
> 
> 
> 
> On 5/22/15 5:50 PM, Justin Bogner wrote:
>> Mathieu Baudet <mathieubaudet at fb.com> writes:
>>> 
>>> The reason is that "tools/clang/include/clang/Config/config.h" (which defines
>>> CLANG_LIBDIR_SUFFIX) is screened by "../llvm/tools/clang/include/clang/Config/
>>> config.h" (which does not).
>> 
>> Why is there a config.h in ../llvm/tools/clang/include/clang/Config/config.h?
>> That directory should only contain config.h.in and config.h.cmake. I
>> think that there's something wrong with your checkout.
> 
> Mathieu, did you at any point run configure from the source directory? That could have created that file in that location. Please check `git st`.
> 
> Note: I really need to get around to turning the "in source builds are deprecated" warning into a hard error... seems it has baked long enough.
> 
> 
> Cheers,
> 
> Jon
> 
> 
> -- 
> Jon Roelofs
> jonathan at codesourcery.com
> CodeSourcery / Mentor Embedded