HIVE-4932 PTFOperator fails resetting PTFPersistence (Navis Ryu via egc)

Submitted by:	Navis Ryu
Reviewed by:	Edward Capriolo

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1507186 13f79535-47bb-0310-9956-ffa450edef68
(cherry picked from commit 72f8b2b7ba1f9c9bc04ec66e620d3b256a3bc2e2)