lib: use helper for readability

Used an extra `checkReusedHandle()` helper function to
increase readability.

PR-URL: https://github.com/nodejs/node/pull/39649


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Darshan Sen <raisinten@gmail.com>