HDFS-3970. Fix bug causing rollback of HDFS upgrade to result in bad VERSION file. Contributed by Vinay and Andrew Wang.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1430037 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' of github.com:griddynamics/yhadoop-common into trunk-gd
Merge branch 'trunk-gd' of github.com:griddynamics/yhadoop-common into fb-HADOOP-9078-trunk-gd