test: l2fwd: increase burst size
test: l2fwd: increase burst size

Increased burst size to 32. This improves packet rate about
15% with netmap, since system call rate is halved.
No harm to any implementation, since implementation decides
how many packets are returned. This is comparable to DPDK l2fwd
burst size.

Signed-off-by: Petri Savolainen <d528fd253b9aaf78fa72edbcc6249e82047f6ce6@nokia.com>
Reviewed-by: Nicolas Morey-Chaisemartin <7188b998d7bb37a035517aa285fa3f5a95344e80@kalray.eu>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

kalray/odp-mppa,kalray/odp-mppa,dkrot/odp,mike-holmes-linaro/odp,kalray/odp-mppa,mike-holmes-linaro/odp,nmorey/odp,nmorey/odp,mike-holmes-linaro/odp,nmorey/odp,dkrot/odp,kalray/odp-mppa,rsalveti/odp,nmorey/odp,kalray/odp-mppa,erachmi/odp,erachmi/odp,rsalveti/odp,mike-holmes-linaro/odp,rsalveti/odp,ravineet-singh/odp,kalray/odp-mppa,ravineet-singh/odp,erachmi/odp,rsalveti/odp,erachmi/odp,dkrot/odp,ravineet-singh/odp,dkrot/odp,rsalveti/odp,ravineet-singh/odp,kalray/odp-mppa