test: fix test/pummel/test-fs-watch-non-recursive.js

test-fs-watch-non-recursive was loading the `common/tmpdir` module as if
it were a built-in and was failing because of it. Fix the path. The test
now works.

PR-URL: https://github.com/nodejs/node/pull/25386


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>