net: Mark flowi arg to flow_cache_uli_match() const.

Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/flow.h

@@ -112,7 +112,8 @@ extern struct flow_cache_object *flow_cache_lookup(
 extern void flow_cache_flush(void);
 extern atomic_t flow_cache_genid;
 
-static inline int flow_cache_uli_match(struct flowi *fl1, struct flowi *fl2)
+static inline int flow_cache_uli_match(const struct flowi *fl1,
+				       const struct flowi *fl2)
 {
 	return (fl1->proto == fl2->proto &&
 		!memcmp(&fl1->uli_u, &fl2->uli_u, sizeof(fl1->uli_u)));