test: fix flaky test-benchmark-events

Make sure each benchmark file only runs one combination of options.
Allow for zero iterations for short benchmark.

PR-URL: https://github.com/nodejs/node/pull/17472
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

test/parallel/test-benchmark-events.js

@@ -4,4 +4,6 @@ require('../common');
 
 const runBenchmark = require('../common/benchmark');
 
-runBenchmark('events', ['n=1']);
+runBenchmark('events',
+             ['argc=0', 'listeners=1', 'n=1'],
+             { NODEJS_BENCHMARK_ZERO_ALLOWED: 1 });