Fix typo about Executor (#1386)
Fix typo about Executor (#1386)

Summary: Pull Request resolved: https://github.com/facebook/folly/pull/1386

Reviewed By: yfeldblum

Differential Revision: D21992975

Pulled By: Orvid

fbshipit-source-id: 7d52e3e9f8db899079263ef15e9f1bbfbedadc44

facebook/folly,facebook/folly,facebook/folly,facebook/folly,facebook/folly