Fix path for fatal library
Fix path for fatal library

Summary:
As titled.

the header is present in installed/fatal/fatal/portability.h
search there.

Differential Revision: D38775841

fbshipit-source-id: 936be1734fc8c65fee8d021a14cfc9fadca12f68

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift