memif: fix the default txq placement
memif: fix the default txq placement

Type: fix

Fixes: 3effb4e63068 ("memif: integrate with new tx infra")

"memif: integrate with new tx infra" patch integrated memif
with new tx infra. There might be scenarios when txqs were
less than vpp threads, in which case, txqs should be shared
among threads. This patch fixes it.

Signed-off-by: Mohsin Kazmi <3be96aed1fe21f963e790909e1d3a8e57ce776f2@cisco.com>
Change-Id: I1c64a1370f5024240ab56311f75665db31714b60

FDio/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,FDio/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp