test/crypto: fix mbuf reset after null check
test/crypto: fix mbuf reset after null check

Use m only after it was checked not to be NULL.

Fixes: 202d375c60bc1 ("app/test: add cryptodev unit and performance tests")
Cc: stable@dpdk.org

Signed-off-by: Thierry Herbelot <6a957105cd34caef8a0a517243bc5f366ed82fb3@6wind.com>
Acked-by: Akhil Goyal <c3c9da6f7a1dc963875aa67cfd85a4c94f75d526@marvell.com>

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