kni: fix build on RHEL 7.5
kni: fix build on RHEL 7.5

Signed-off-by: Lee Roberts <e3aa10cfae54480c7b5e592e343578078ca7a6d4@hpe.com>
Acked-by: Ferruh Yigit <ba8734c3c506d2e3557bd4ac8fdaccd25bdb9aa7@intel.com>

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