xfrm: Const'ify sec_path arg to secpath_has_nontransport.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 2de0bc2..41a91d2 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1994,7 +1994,7 @@
 }
 EXPORT_SYMBOL(__xfrm_decode_session);
 
-static inline int secpath_has_nontransport(struct sec_path *sp, int k, int *idxp)
+static inline int secpath_has_nontransport(const struct sec_path *sp, int k, int *idxp)
 {
 	for (; k < sp->len; k++) {
 		if (sp->xvec[k]->props.mode != XFRM_MODE_TRANSPORT) {