net: fix IPv4 IHL and VHL define
net: fix IPv4 IHL and VHL define

Fix the RTE_IPV4_VHL_DEF macro that represents the value
for the IPv4 VHL and Minimum IHL header fields according to
rfc791.

Fixes: 2318d8d54565 ("net: define IPv4 IHL and VHL")
Cc: stable@dpdk.org

Reported-by: David Harton <41e0a1e2bcc9f6ca8a5f4060a6583dfdda62fd96@cisco.com>
Signed-off-by: Flavia Musatescu <08b0ac2f219c2a4095a8ee027157afceb099c374@intel.com>
Reviewed-by: Ferruh Yigit <ba8734c3c506d2e3557bd4ac8fdaccd25bdb9aa7@intel.com>

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