Use appropriate completion handler in PerfTestMulti scenarios

The tests run from PerfTestMulti would be running with
MulticastSet.NoLimitCompletionHandler, so they would never stop. They
now use the appropriate completion handler by relying on
PerfTest#getCompletionHandler.

Fixes #95

Author: acogoluegnes

src/main/java/com/rabbitmq/perf/SimpleScenario.java

@@ -46,7 +46,7 @@ public void run()
         throws IOException, InterruptedException, TimeoutException, NoSuchAlgorithmException, KeyManagementException, URISyntaxException, ExecutionException {
         this.stats = new SimpleScenarioStats(interval);
         for (MulticastParams p : params) {
-            MulticastSet set = new MulticastSet(stats, factory, p, null, new MulticastSet.NoLimitCompletionHandler());
+            MulticastSet set = new MulticastSet(stats, factory, p, null, PerfTest.getCompletionHandler(p));
             stats.setup(p);
             set.run();
         }

src/main/java/com/rabbitmq/perf/VaryingScenario.java

@@ -60,7 +60,7 @@ private void run(Variable[] variables, List<VariableValue> values) throws Except
                 for (VariableValue value : values) {
                     value.setup(p);
                 }
-                MulticastSet set = new MulticastSet(stats0, factory, p, null, new MulticastSet.NoLimitCompletionHandler());
+                MulticastSet set = new MulticastSet(stats0, factory, p, null, PerfTest.getCompletionHandler(p));
                 stats0.setup(p);
                 set.run();
                 for (VariableValue value : values) {