[erl-doc] fixed typo
[erl-doc] fixed typo

Summary: The closed file is the argument, not the returned value.

Reviewed By: kren1

Differential Revision: D36700995

fbshipit-source-id: 95aaa084c1eb450c5d3513e52db2685d77927a46

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