The code making sure sctp payload be multiple of 4 to determin TX_SCP_CKSUM in
process_inner_cksums() of csumonly.c should convert ipv4_hdr->total_length to
host byte order. The following is the code segment.

```
        } else if (info->l4_proto == IPPROTO_SCTP) {
                sctp_hdr = (struct rte_sctp_hdr *)
                        ((char *)l3_hdr + info->l3_len);
                /* sctp payload must be a multiple of 4 to be
                 * offloaded */
                if ((tx_offloads & RTE_ETH_TX_OFFLOAD_SCTP_CKSUM) &&
                        ((ipv4_hdr->total_length & 0x3) == 0)) {
                        ol_flags |= RTE_MBUF_F_TX_SCTP_CKSUM;
                } else {
                        sctp_hdr->cksum = 0;
                        /* XXX implement CRC32c, example available in
                         * RFC3309 */
                }
        }
```