DPDK: minor post review fix (two rings per lcore)
DPDK: minor post review fix (two rings per lcore)

Closes-bug: 1513842

Change-Id: I222a493e7b2ac4ab8cb0ed7041e2f3b79c471c8b

codilime/contrail-vrouter,codilime/contrail-vrouter,codilime/contrail-vrouter,codilime/contrail-vrouter