fix test breakage after: https://issues.apache.org/jira/browse/AMQ-3833

Depending on timing of events in the test the producer audit can land on the last log file so there can be one or two left.

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1434514 13f79535-47bb-0310-9956-ffa450edef68