src: check uv_fs_close() return value

Coverity was complaining about not checking the return value.

PR-URL: https://github.com/nodejs/node/pull/26967


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>