Fix bug with finding errors on stdout

Author: bterlson

lib/agentPool.js

@@ -30,8 +30,7 @@ function makePool(agentCount, hostType, hostArgs, hostPath) {
     .then(result => {
       pool.onNext(agent);
       test.rawResult = result;
-
-      const doneError = record.stdout.match(/^test262\/error (.*)$/gm); 
+      const doneError = result.stdout.match(/^test262\/error (.*)$/gm); 
       if (doneError) {
         const lastErrorString = doneError[doneError.length - 1];
         const errorMatch = lastErrorString.match(/test262\/error ([^:]+): (.*)/);