[sledge] Fix doc of List.remove_exn
[sledge] Fix doc of List.remove_exn

Reviewed By: jvillard

Differential Revision: D20863527

fbshipit-source-id: 807eb0e51

jvillard/infer,facebook/infer,facebook/infer,jvillard/infer,facebook/infer,facebook/infer,facebook/infer,facebook/infer,jvillard/infer,jvillard/infer,facebook/infer,jvillard/infer,jvillard/infer,jvillard/infer