src: inline HostentToAddresses()

With the removal of `GetHostByNameWrap` in the previous commit, there
is only one remaining call site.  Inlining it there lets us simplify
the logic.

PR-URL: https://github.com/nodejs/node/pull/17860


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>