xfrm: add UDP encapsulation port in migrate message

Add XFRMA_ENCAP, UDP encapsulation port, to km_migrate announcement
to userland. Only add if XFRMA_ENCAP was in user migrate request.

Signed-off-by: Antony Antony <antony@phenome.org>
Reviewed-by: Richard Guy Briggs <rgb@tricolour.ca>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index b76e673..f2421c6 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1964,7 +1964,8 @@
 #ifdef CONFIG_XFRM_MIGRATE
 int km_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
 	       const struct xfrm_migrate *m, int num_migrate,
-	       const struct xfrm_kmaddress *k)
+	       const struct xfrm_kmaddress *k,
+	       const struct xfrm_encap_tmpl *encap)
 {
 	int err = -EINVAL;
 	int ret;
@@ -1973,7 +1974,8 @@
 	rcu_read_lock();
 	list_for_each_entry_rcu(km, &xfrm_km_list, list) {
 		if (km->migrate) {
-			ret = km->migrate(sel, dir, type, m, num_migrate, k);
+			ret = km->migrate(sel, dir, type, m, num_migrate, k,
+					  encap);
 			if (!ret)
 				err = ret;
 		}