benchmark: fix punycode and get-ciphers benchmark

Add missing 'i=0' from for-loops from punycode and get-ciphers
benchmarks.

PR-URL: https://github.com/nodejs/node/pull/11720


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>