test: improve debug output in trace-events test

test-trace-events-fs-sync is swallowing useful information when it
fails. This change results in more information being displayed.

PR-URL: https://github.com/nodejs/node/pull/21120


Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Lance Ball <lball@redhat.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>