test/performance: pktio: perform an initial warmup run
test/performance: pktio: perform an initial warmup run

The results from the initial test run are often worse than would
normally be expected due to there being no warm up phase. As a
simple way to warm up run first test stage twice, ignoring the
results of the first run.

Signed-off-by: Stuart Haslam <1fce01f364ef5298e64e07a42e08efeef153fa98@linaro.org>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

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