Fix LD_LIBRARY_PATH behavior
Fix LD_LIBRARY_PATH behavior

Summary: Reinstating D31458633 (https://github.com/facebook/SoLoader/commit/727ab9695827467e7d3bcac6e96b544a7b84005f)

Reviewed By: simpleton

Differential Revision: D31664187

fbshipit-source-id: 5b3ea787380d6643af0fb5fe80839aef01619fcd

facebook/SoLoader,facebook/SoLoader,facebook/SoLoader