app/crypto-perf: close device after benchmark run
app/crypto-perf: close device after benchmark run

This patch adds closing of the PMD after running the benchmark.

Signed-off-by: Adam Dybkowski <b636839fd6da8c90d3d28fcb76555ed5d2c5a673@intel.com>
Acked-by: Akhil Goyal <c3c9da6f7a1dc963875aa67cfd85a4c94f75d526@marvell.com>

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