rte_pktmbuf_attach copies the packet meta data but does not
copy the offload flags. This means that cloned packets lose
their offload settings such as vlan tag.

Signed-off-by: Stephen Hemminger <shemming@brocade.com>

--- a/lib/librte_mbuf/rte_mbuf.h	2013-12-06 08:39:43.000000000 -0800
+++ b/lib/librte_mbuf/rte_mbuf.h	2014-03-06 15:16:44.525440437 -0800
@@ -624,6 +624,7 @@ static inline void rte_pktmbuf_attach(st
 	mi->pkt.next = NULL;
 	mi->pkt.pkt_len = mi->pkt.data_len;
 	mi->pkt.nb_segs = 1;
+	mi->ol_flags = md->ol_flags;
 
 	__rte_mbuf_sanity_check(mi, RTE_MBUF_PKT, 1);
 	__rte_mbuf_sanity_check(md, RTE_MBUF_PKT, 0);