test/crypto: fix build with GCC 11
test/crypto: fix build with GCC 11

Fix the allocation for sessions, to prevent an array-bounds
warning with GCC 11. Set the not created session to NULL.

Fixes: 202d375c60bc ("app/test: add cryptodev unit and performance tests")
Cc: stable@dpdk.org

Signed-off-by: Kevin Traynor <1f46c93815774a2e602547cf1e37c682d62b566d@redhat.com>
Acked-by: Akhil Goyal <c3c9da6f7a1dc963875aa67cfd85a4c94f75d526@marvell.com>

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