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

(cherry picked from commit a08262d8769808dd3a8ee1b1e80fbf6ac13a557c)
Signed-off-by: Reynold Xin <rxin@apache.org>