benchmark: fix typo in _http-benchmarkers.js

PR-URL: https://github.com/nodejs/node/pull/12455
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

benchmark/_http-benchmarkers.js

@@ -175,7 +175,7 @@ exports.run = function(options, callback) {
     const result = benchmarker.processResults(stdout);
     if (result === undefined) {
       callback(new Error(
-        `${options.benchmarker} produced strange output: ${stdout}`, code));
+        `${options.benchmarker} produced strange output: ${stdout}`), code);
       return;
     }