HIVE-6287: batchSize computation in Vectorized ORC reader can cause BufferUnderFlowException when PPD is enabled (Prasanth J via Gunther Hagleitner)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1563260 13f79535-47bb-0310-9956-ffa450edef68