[PATCH v3 1/2] examples/l3fwd: use single set of variables throughout the code

[Thomas Monjalon]

> nb_rxd and nb_txd are used in polling mode and event mode of operation. nb_rxd and nb_txd are already global in polling mode but are not visible to event mode code. Make them visible to all parts of the application.
> 
> Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> Reviewed-by: Kathleen Capella <kathleen.capella at arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
> Acked-by: Bruce Richardson <bruce.richardson at intel.com>
> 
> Tested-by: Yingya Han < yingyax.han at intel.com>

Applied, thanks.