HIVE-4745 : java.lang.RuntimeException: Hive Runtime Error while closing operators: java.lang.ClassCastException: org.apache.hadoop.io.NullWritable cannot be cast to org.apache.hadoop.hive.serde2.io.DoubleWritable (Jitendra Nath Pandey via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/vectorization@1495534 13f79535-47bb-0310-9956-ffa450edef68