af_key: fix SADB_X_SPDDELETE response

When deleting an SPD entry using SADB_X_SPDDELETE, c.data.byid is not
initialized to zero in pfkey_spddelete(). Thus, key_notify_policy()
responds with a PF_KEY message of type SADB_X_SPDDELETE2 instead of
SADB_X_SPDDELETE.

Signed-off-by: Tobias Brunner <tobias.brunner@strongswan.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/key/af_key.c

@@ -2341,6 +2341,7 @@ static int pfkey_spddelete(struct sock *sk, struct sk_buff *skb, struct sadb_msg
 
 	c.seq = hdr->sadb_msg_seq;
 	c.pid = hdr->sadb_msg_pid;
+	c.data.byid = 0;
 	c.event = XFRM_MSG_DELPOLICY;
 	km_policy_notify(xp, pol->sadb_x_policy_dir-1, &c);