net: tcp: remove call to obsolete crypto_ahash_alignmask()

linux-next hit the following build error:

net/ipv4/tcp_ao.c: In function 'tcp_ao_key_alloc':
net/ipv4/tcp_ao.c:1536:13: error: implicit declaration of function 'crypto_ahash_alignmask'; did you mean 'crypto_ahash_alg_name'? [-Werror=implicit-function-declaration]
 1536 |         if (crypto_ahash_alignmask(tfm) > TCP_AO_KEY_ALIGN) {
      |             ^~~~~~~~~~~~~~~~~~~~~~
      |             crypto_ahash_alg_name

Caused by commit from the crypto tree

  0f8660c ("crypto: ahash - remove crypto_ahash_alignmask")

interacting with commit

  4954f17 ("net/tcp: Introduce TCP_AO setsockopt()s")

from networking. crypto_ahash_alignmask() has been phased out
by the former commit, drop the call in networking.
Eric confirms that the check is safe to remove and was questionable
here in the first place.

Signed-off-by: Stephen Rothwell <[email protected]>
Acked-by: Herbert Xu <[email protected]>
Reviewed-by: Dmitry Safonov <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

net/ipv4/tcp_ao.c

@@ -1533,10 +1533,6 @@ static struct tcp_ao_key *tcp_ao_key_alloc(struct sock *sk,
 		goto err_free_pool;
 
 	tfm = crypto_ahash_reqtfm(hp.req);
-	if (crypto_ahash_alignmask(tfm) > TCP_AO_KEY_ALIGN) {
-		err = -EOPNOTSUPP;
-		goto err_pool_end;
-	}
 	digest_size = crypto_ahash_digestsize(tfm);
 	tcp_sigpool_end(&hp);
 
@@ -1551,8 +1547,6 @@ static struct tcp_ao_key *tcp_ao_key_alloc(struct sock *sk,
 	key->digest_size = digest_size;
 	return key;
 
-err_pool_end:
-	tcp_sigpool_end(&hp);
 err_free_pool:
 	tcp_sigpool_release(pool_id);
 	return ERR_PTR(err);