net: move *skb_get_poff declarations into correct header

Since these functions are defined in flow_dissector.c, move header
declarations from skbuff.h into flow_dissector.h

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 118ae69..4570cca 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -46,6 +46,9 @@
 }
 
 u32 flow_hash_from_keys(struct flow_keys *keys);
+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);
 
 /* struct flow_keys_digest:
  *