[CDH5] Fix test spilling.

tpch in cdh5 does not have double columns. Also, remove round calls to test that we get
consistent results.

Change-Id: Ia45ef08644ed78b05a08c47422733ab38a26b508
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4595
Reviewed-by: Ishaan Joshi <ishaan@cloudera.com>
Tested-by: Ishaan Joshi <ishaan@cloudera.com>