ah: Remove obsolete code

ah4 and ah6 are converted to ahash now, so we can remove the
code for the obsolete hash algorithm.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ah.h

 #ifndef _NET_AH_H
 #define _NET_AH_H
 
-#include <linux/crypto.h>
-#include <net/xfrm.h>
+#include <linux/skbuff.h>
 
 /* This is the maximum truncated ICV length that we know of. */
 #define MAX_AH_AUTH_LEN	12
 
+struct crypto_ahash;
+
 struct ah_data
 {
-	u8			*work_icv;
 	int			icv_full_len;
 	int			icv_trunc_len;
 
-	struct crypto_hash	*tfm;
 	struct crypto_ahash	*ahash;
 };
 
-static inline int ah_mac_digest(struct ah_data *ahp, struct sk_buff *skb,
-				u8 *auth_data)
-{
-	struct hash_desc desc;
-	int err;
-
-	desc.tfm = ahp->tfm;
-	desc.flags = 0;
-
-	memset(auth_data, 0, ahp->icv_trunc_len);
-	err = crypto_hash_init(&desc);
-	if (unlikely(err))
-		goto out;
-	err = skb_icv_walk(skb, &desc, 0, skb->len, crypto_hash_update);
-	if (unlikely(err))
-		goto out;
-	err = crypto_hash_final(&desc, ahp->work_icv);
-
-out:
-	return err;
-}
-
 struct ip_auth_hdr;
 
 static inline struct ip_auth_hdr *ip_auth_hdr(const struct sk_buff *skb)