xfrm: clone mark when cloning policy

When we clone the SP, we should also clone the mark.
Useful for socket based SPs.

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 2a6e646..34a5ef8 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1154,6 +1154,7 @@
 		}
 		newp->lft = old->lft;
 		newp->curlft = old->curlft;
+		newp->mark = old->mark;
 		newp->action = old->action;
 		newp->flags = old->flags;
 		newp->xfrm_nr = old->xfrm_nr;