test/crypto: do not allocate extra memory for digest
test/crypto: do not allocate extra memory for digest

Now that PMDs do not need extra space in the mbuf
to store temporarily the digest when verifying
an authentication tag, it is not required to allocate
more memory in the mbufs passed to cryptodev.

Signed-off-by: Pablo de Lara <28355d9cfe41bb8148aea0fb24f47aae8f4217a1@intel.com>
Acked-by: Fan Zhang <b46d470dc79aa6fd718cd24d07380f6203b7fc3c@intel.com>

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