xfrm: Const'ify selector args in xfrm_migrate paths.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 17b296b..1806c91 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1493,7 +1493,7 @@
 extern struct xfrm_state * xfrm_migrate_state_find(struct xfrm_migrate *m);
 extern struct xfrm_state * xfrm_state_migrate(struct xfrm_state *x,
 					      struct xfrm_migrate *m);
-extern int xfrm_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
+extern int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
 			struct xfrm_migrate *m, int num_bundles,
 			struct xfrm_kmaddress *k);
 #endif