aesni_mb: fix null pointer dereferencing
aesni_mb: fix null pointer dereferencing

Fix null pointer dereferencing by reporting if null and
exiting the function.

Coverity issue: 126584
Fixes: c0f87eb5252b ("cryptodev: change burst API to be crypto op oriented")

Signed-off-by: Deepak Kumar Jain <9bf453c83e22b0c9e2b3754d419540ea41e2427f@intel.com>
Acked-by: Pablo de Lara <28355d9cfe41bb8148aea0fb24f47aae8f4217a1@intel.com>

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