test: correct order of args in buffer compare

PR-URL: https://github.com/nodejs/node/pull/23521


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Hitesh Kanwathirtha <digitalinfinity@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>