gpperfmon: remove unused variable
gpperfmon: remove unused variable

Signed-off-by: Marbin Tan <fe9db60e23a06449b90b19d66b721708068089ad@pivotal.io>

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