benchmark: honor n in perf_hooks usertiming

Signed-off-by: RafaelGSS <rafael.nunu@hotmail.com>
PR-URL: https://github.com/nodejs/node/pull/66746
Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>
Reviewed-By: Vinícius Lourenço Claro Cardoso <contact@viniciusl.com.br>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

benchmark/perf_hooks/usertiming.js

@@ -29,6 +29,6 @@ function main({ n, observe }) {
 
   bench.start();
   performance.mark('start');
-  for (let i = 0; i < 1e5; i++)
+  for (let i = 0; i < n; i++)
     test();
 }