xfrm: Prepare for CRYPTO_MAX_ALG_NAME expansion

This patch fixes the xfrm_user code to use the actual array size
rather than the hard-coded CRYPTO_MAX_ALG_NAME length.  This is
because the array size is fixed at 64 bytes while we want to increase
the in-kernel CRYPTO_MAX_ALG_NAME value.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>

net/xfrm/xfrm_user.c

@@ -55,7 +55,7 @@ static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
 		return -EINVAL;
 	}
 
-	algp->alg_name[CRYPTO_MAX_ALG_NAME - 1] = '\0';
+	algp->alg_name[sizeof(algp->alg_name) - 1] = '\0';
 	return 0;
 }
 
@@ -71,7 +71,7 @@ static int verify_auth_trunc(struct nlattr **attrs)
 	if (nla_len(rt) < xfrm_alg_auth_len(algp))
 		return -EINVAL;
 
-	algp->alg_name[CRYPTO_MAX_ALG_NAME - 1] = '\0';
+	algp->alg_name[sizeof(algp->alg_name) - 1] = '\0';
 	return 0;
 }
 
@@ -87,7 +87,7 @@ static int verify_aead(struct nlattr **attrs)
 	if (nla_len(rt) < aead_len(algp))
 		return -EINVAL;
 
-	algp->alg_name[CRYPTO_MAX_ALG_NAME - 1] = '\0';
+	algp->alg_name[sizeof(algp->alg_name) - 1] = '\0';
 	return 0;
 }