lib: fix typo in comments in module.js

A minor typo in comments, no logic changes.

PR-URL: https://github.com/nodejs/node/pull/12528


Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: David Cai <davidcai1993@yahoo.com>
Reviewed-By: Jeremy Whitlock <jwhitlock@apache.org>