The return value for a test when the required PMD is not loaded should
be TEST_SKIPPED, rather than TEST_FAILED.
Fixes: 8bfdd8a7f0f1 ("test/crypto: refactor to use sub test suites")
Signed-off-by: Ciara Power <ciara.power@intel.com>
Acked-by: Fan Zhang <roy.fan.zhang@intel.com>