private synchronized void unschedule(Entry entry) {
        if (entry.next != null) {
            linkOut(entry);
        }
    }
@author <a href="mailto:havardpe@yahoo-inc.com">Haavard Pettersen</a>
@author Simon Thoresen Hult
jdisc_core/src/main/java/com/yahoo/jdisc/core/ScheduledQueue.java