[cli] remove support for INFERCLANG_ARGS
[cli] remove support for INFERCLANG_ARGS

Summary: This has been deprecated for a while.

Reviewed By: jeremydubreil

Differential Revision: D4430179

fbshipit-source-id: 2c3a430

ryoon/infer,ropas/infer,ropas/infer,ropas/infer,blzq/infer,jvillard/infer,jvillard/infer,ropas/infer,ryoon/infer,ryoon/infer,facebook/infer,jsachs/infer,blzq/infer,facebook/infer,jvillard/infer,facebook/infer,ropas/infer,jsachs/infer,jsachs/infer,blzq/infer,ryoon/infer,blzq/infer,facebook/infer,blzq/infer,jvillard/infer,jvillard/infer,jvillard/infer,ryoon/infer,jsachs/infer,jsachs/infer,ropas/infer,facebook/infer,ryoon/infer,jsachs/infer,facebook/infer,blzq/infer,facebook/infer,jvillard/infer