Avoid hashing partitions without rules set
Avoid hashing partitions without rules set

If there are no rules on the PartitionInfo the hashing will perform
a (foo % 0) which is an undefined operator.

Per report from Coverity.

yuanzhao/gpdb,Quikling/gpdb,jmcatamney/gpdb,edespino/gpdb,lisakowen/gpdb,50wu/gpdb,50wu/gpdb,kaknikhil/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,50wu/gpdb,edespino/gpdb,Chibin/gpdb,rvs/gpdb,50wu/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,Quikling/gpdb,adam8157/gpdb,ashwinstar/gpdb,lisakowen/gpdb,edespino/gpdb,greenplum-db/gpdb,xinzweb/gpdb,Quikling/gpdb,rvs/gpdb,edespino/gpdb,cjcjameson/gpdb,xinzweb/gpdb,adam8157/gpdb,cjcjameson/gpdb,rvs/gpdb,lisakowen/gpdb,yuanzhao/gpdb,xinzweb/gpdb,jmcatamney/gpdb,lintzc/gpdb,cjcjameson/gpdb,lintzc/gpdb,kaknikhil/gpdb,xinzweb/gpdb,lintzc/gpdb,Chibin/gpdb,xinzweb/gpdb,janebeckman/gpdb,ashwinstar/gpdb,xinzweb/gpdb,kaknikhil/gpdb,Chibin/gpdb,janebeckman/gpdb,lisakowen/gpdb,janebeckman/gpdb,50wu/gpdb,janebeckman/gpdb,janebeckman/gpdb,greenplum-db/gpdb,rvs/gpdb,edespino/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,janebeckman/gpdb,lisakowen/gpdb,lisakowen/gpdb,rvs/gpdb,kaknikhil/gpdb,50wu/gpdb,janebeckman/gpdb,edespino/gpdb,lisakowen/gpdb,50wu/gpdb,adam8157/gpdb,edespino/gpdb,rvs/gpdb,Quikling/gpdb,lisakowen/gpdb,janebeckman/gpdb,ashwinstar/gpdb,rvs/gpdb,Chibin/gpdb,Quikling/gpdb,cjcjameson/gpdb,kaknikhil/gpdb,adam8157/gpdb,jmcatamney/gpdb,Chibin/gpdb,Chibin/gpdb,Quikling/gpdb,greenplum-db/gpdb,yuanzhao/gpdb,adam8157/gpdb,xinzweb/gpdb,lintzc/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,yuanzhao/gpdb,adam8157/gpdb,cjcjameson/gpdb,edespino/gpdb,Quikling/gpdb,edespino/gpdb,greenplum-db/gpdb,Quikling/gpdb,Chibin/gpdb,ashwinstar/gpdb,lintzc/gpdb,kaknikhil/gpdb,Chibin/gpdb,janebeckman/gpdb,edespino/gpdb,greenplum-db/gpdb,rvs/gpdb,janebeckman/gpdb,lintzc/gpdb,lintzc/gpdb,Chibin/gpdb,Chibin/gpdb,kaknikhil/gpdb,Quikling/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,adam8157/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,jmcatamney/gpdb,rvs/gpdb,yuanzhao/gpdb,rvs/gpdb,adam8157/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,lintzc/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,greenplum-db/gpdb,50wu/gpdb,jmcatamney/gpdb,xinzweb/gpdb,lintzc/gpdb,jmcatamney/gpdb,Quikling/gpdb