Bug in fix for #2296?

[Jason Harvey]

I applied the #2296 patch and retried a scrub. Now getting thousands
of the following:

java.io.IOException: Keys must be written in ascending order.
        at 
org.apache.cassandra.io.sstable.SSTableWriter.beforeAppend(SSTableWriter.java:111)
        at 
org.apache.cassandra.io.sstable.SSTableWriter.append(SSTableWriter.java:128)
        at 
org.apache.cassandra.db.CompactionManager.doScrub(CompactionManager.java:598)
        at 
org.apache.cassandra.db.CompactionManager.access$600(CompactionManager.java:56)
        at 
org.apache.cassandra.db.CompactionManager$3.call(CompactionManager.java:195)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
        at java.util.concurrent.FutureTask.run(FutureTask.java:166)
        at 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
        at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
        at java.lang.Thread.run(Thread.java:636)