HDFS-4883. complete() should verify fileId. Contributed by Tao Luo.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1495302 13f79535-47bb-0310-9956-ffa450edef68
Move changes for HDFS-4883 to 2.1.0 section.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1495314 13f79535-47bb-0310-9956-ffa450edef68