Fix memory leak in PartitionedAggNode
Fix memory leak in PartitionedAggNode

Change-Id: Ifedffde3d67102bf8e4ab5a46d68812f49341bdb
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4809
Reviewed-by: Nong Li <99a5e5f8f5911755b88e0b536d46aafa102bed41@cloudera.com>
Tested-by: jenkins

ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC