benchmark: update comment in common.js

Very minor update in benchmark/common.js
Not exactly a critical change, just continued cleaning
out of old joyent/node PRs that never landed.

benchmark/common.js

@@ -137,7 +137,7 @@ Benchmark.prototype._run = function() {
   if (this.config)
     return this.fn(this.config);
 
-  // one more more options weren't set.
+  // some options weren't set.
   // run with all combinations
   var main = require.main.filename;
   var settings = [];