src: cleanup in all return paths in node::Start

`node::Start` creates a number of artifacts in its scope which are
cleaned up in the exit path, but there is at least one path where the
cleanups are bypassed. Force all paths follow the exit sequence.

Refs: https://github.com/nodejs/node/pull/21283
PR-URL: https://github.com/nodejs/node/pull/26471


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>