HIVE-7389: Reduce number of metastore calls in MoveTask (when loading dynamic partitions) (Rajesh Balamohan via Gunther Hagleitner)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.14@1628282 13f79535-47bb-0310-9956-ffa450edef68