examples/ipsec-secgw: fix crash on unsupported algo
examples/ipsec-secgw: fix crash on unsupported algo

If algo is NULL set the status to error and return. This change
prevent crashing of ipsec-secgw application when a specific
cipher/auth/aead algo are not supported by application.

Fixes: 0d547ed03717 ("examples/ipsec-secgw: support configuration file")
Cc: stable@dpdk.org

Signed-off-by: Savinay Dharmappa <b9bdbfc60b49ae384b99e3313b3f20d055baeacb@intel.com>
Acked-by: Konstantin Ananyev <cbd5212b59ab42a210d72992d23a3aa17cfd3eaf@intel.com>

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