test/distributor: fix flush with worker shutdown
test/distributor: fix flush with worker shutdown

On restarting worker 0 after shutdown, packets handled by
worker 0 must be incremented only when a packet is received by
it.

Fixes: c3eabff124e6 ("distributor: add unit tests")
Cc: stable@dpdk.org

Signed-off-by: Harman Kalra <568a3484dfecf16d6b30cd214c570848bb408570@marvell.com>
Acked-by: David Hunt <763be7c8e0ad91e03160e7aed76d5cd41534e2f9@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk