test/crypto: fix return value of a skipped test

test/crypto: fix return value of a skipped test

The blockcipher testcase return value TEST_SUCCESS was incorrect for
one conditional check, it should have been TEST_SKIPPED similar to the
other condition checks in this function when the testcase is skipped.

Fixes: 4868f6591c6f ("test/crypto: add cases for raw datapath API")
Cc: stable@dpdk.org
Signed-off-by: Ciara Power <ciara.power@intel.com>
Acked-by: Akhil Goyal <gakhil@marvell.com>
Acked-by: Declan Doherty <declan.doherty@intel.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Tested-by: Ruifeng Wang <ruifeng.wang@arm.com>