xfrm: rename struct xfrm_filter

iproute2 already defines a structure with that name, let's use another one to
avoid any conflict.

CC: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/key/af_key.c b/net/key/af_key.c
index a50d979..12651b4 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1799,7 +1799,7 @@
 static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_msg *hdr, void * const *ext_hdrs)
 {
 	u8 proto;
-	struct xfrm_filter *filter = NULL;
+	struct xfrm_address_filter *filter = NULL;
 	struct pfkey_sock *pfk = pfkey_sk(sk);
 
 	if (pfk->dump.dump != NULL)