Update LBFGSSuite.scala

the same reason as https://github.com/apache/spark/pull/588

Author: baishuo(白硕) <vc_java@hotmail.com>

Closes #815 from baishuo/master and squashes the following commits:

6876c1e [baishuo(白硕)] Update LBFGSSuite.scala
bugfix
Merge branch 'master' of https://github.com/apache/spark into cleanup_checkpoint_date_als