mbuf: fix big endian build
mbuf: fix big endian build

Compilation was failing when using a big endian toolchain:

rte_mbuf.h:504:2: error: expected ',' or '}' before 'RTE_MBUF_L3_LEN_OFS'

Fixes: 8d9c2c3a1f01 ("mbuf: add function to generate raw Tx offload value")

Signed-off-by: Thomas Monjalon <5f50a84c1fa3bcff146405017f36aec1a10a9e38@monjalon.net>
Acked-by: Konstantin Ananyev <cbd5212b59ab42a210d72992d23a3aa17cfd3eaf@intel.com>

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