crypto/qat: fix allocation check and leak

crypto/qat: fix allocation check and leak

There are several func calls to rte_zmalloc() which don't do null
point check on the return value. And before return, the memory is not
freed. Fix it by adding null point check and rte_free().

Fixes: 1703e94ac5ce ("qat: add driver for QuickAssist devices")
Fixes: e09231eaa2af ("crypto/qat: add SGL capability")
Cc: stable@dpdk.org
Signed-off-by: Yong Wang <wang.yong19@zte.com.cn>
Acked-by: Fiona Trahe <fiona.trahe@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>