Add missing rte_mbuf size in mempool allocation for
out-of-place operation.
Fixes: bf9d6702eca9 ("app/crypto-perf: use single mempool")
Cc: stable@dpdk.org
Signed-off-by: Kai Ji <kai.ji@intel.com>
Acked-by: Fan Zhang <roy.fan.zhang@intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>