crypto: api - Change crypto_unregister_instance argument type

This patch makes crypto_unregister_instance take a crypto_instance
instead of a crypto_alg.  This allows us to remove a duplicate
CRYPTO_ALG_INSTANCE check in crypto_unregister_instance.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/algapi.c

@@ -551,17 +551,13 @@ int crypto_register_instance(struct crypto_template *tmpl,
 }
 EXPORT_SYMBOL_GPL(crypto_register_instance);
 
-int crypto_unregister_instance(struct crypto_alg *alg)
+int crypto_unregister_instance(struct crypto_instance *inst)
 {
-	struct crypto_instance *inst = (void *)alg;
 	LIST_HEAD(list);
 
-	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
-		return -EINVAL;
-
 	down_write(&crypto_alg_sem);
 
-	crypto_remove_spawns(alg, &list, NULL);
+	crypto_remove_spawns(&inst->alg, &list, NULL);
 	crypto_remove_instance(inst, &list);
 
 	up_write(&crypto_alg_sem);

crypto/crypto_user.c

@@ -316,7 +316,7 @@ static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (atomic_read(&alg->cra_refcnt) != 1)
 		return -EBUSY;
 
-	return crypto_unregister_instance(alg);
+	return crypto_unregister_instance((struct crypto_instance *)alg);
 }
 
 static struct crypto_alg *crypto_user_skcipher_alg(const char *name, u32 type,

include/crypto/algapi.h

@@ -137,7 +137,7 @@ struct crypto_template *crypto_lookup_template(const char *name);
 
 int crypto_register_instance(struct crypto_template *tmpl,
 			     struct crypto_instance *inst);
-int crypto_unregister_instance(struct crypto_alg *alg);
+int crypto_unregister_instance(struct crypto_instance *inst);
 
 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
 		      struct crypto_instance *inst, u32 mask);