test: refactor parallel/test-tls-cert-chains-concat

Added common.mustCall and replaced function with arrow function.

PR-URL: https://github.com/nodejs/node/pull/19096
Fixes: https://github.com/nodejs/node/issues/14544


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>