HIVE-6761: Hashcode computation does not use maximum parallelism for scalable dynamic partitioning
 (Prasanth J via Gunther Hagleitner)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/branch-0.13@1582599 13f79535-47bb-0310-9956-ffa450edef68