HDFS-4165. Faulty sanity check in FsDirectory.unprotectedSetQuota. Contributed by Binglin Chang.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1407245 13f79535-47bb-0310-9956-ffa450edef68
(cherry picked from commit 0f7a4337ac96141db4a3400fd8308436d87042f4)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt