flow_dissector: __skb_get_hash_symmetric arg can be const

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -1086,7 +1086,7 @@ __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
 }
 
 void __skb_get_hash(struct sk_buff *skb);
-u32 __skb_get_hash_symmetric(struct sk_buff *skb);
+u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
 u32 skb_get_poff(const struct sk_buff *skb);
 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 		   const struct flow_keys *keys, int hlen);

net/core/flow_dissector.c

@@ -723,7 +723,7 @@ EXPORT_SYMBOL(make_flow_keys_digest);
 
 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
 
-u32 __skb_get_hash_symmetric(struct sk_buff *skb)
+u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
 {
 	struct flow_keys keys;