perf_hooks: remove unnecessary assignment when name is undefined

PR-URL: https://github.com/nodejs/node/pull/32910


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Zeyu Yang <himself65@outlook.com>
Reviewed-By: Andrey Pechkurov <apechkurov@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>