geneve: move definition of geneve_hdr() to geneve.h

This is a static inline with identical definitions in multiple places...

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/geneve.h b/include/net/geneve.h
index 14fb8d3..2a0543a 100644
--- a/include/net/geneve.h
+++ b/include/net/geneve.h
@@ -62,6 +62,11 @@
 	struct geneve_opt options[];
 };
 
+static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
+{
+	return (struct genevehdr *)(udp_hdr(skb) + 1);
+}
+
 #ifdef CONFIG_INET
 struct geneve_sock;