crypto: hctr2 - Only access common skcipher fields on spawn

As skcipher spawns may be of the type lskcipher, only the common
fields may be accessed.  This was already the case but use the
correct helpers to make this more obvious.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/hctr2.c

@@ -406,10 +406,10 @@ static int hctr2_create_common(struct crypto_template *tmpl,
 			       const char *xctr_name,
 			       const char *polyval_name)
 {
+	struct skcipher_alg_common *xctr_alg;
 	u32 mask;
 	struct skcipher_instance *inst;
 	struct hctr2_instance_ctx *ictx;
-	struct skcipher_alg *xctr_alg;
 	struct crypto_alg *blockcipher_alg;
 	struct shash_alg *polyval_alg;
 	char blockcipher_name[CRYPTO_MAX_ALG_NAME];
@@ -431,7 +431,7 @@ static int hctr2_create_common(struct crypto_template *tmpl,
 				   xctr_name, 0, mask);
 	if (err)
 		goto err_free_inst;
-	xctr_alg = crypto_spawn_skcipher_alg(&ictx->xctr_spawn);
+	xctr_alg = crypto_spawn_skcipher_alg_common(&ictx->xctr_spawn);
 
 	err = -EINVAL;
 	if (strncmp(xctr_alg->base.cra_name, "xctr(", 5))
@@ -500,8 +500,8 @@ static int hctr2_create_common(struct crypto_template *tmpl,
 	inst->alg.decrypt = hctr2_decrypt;
 	inst->alg.init = hctr2_init_tfm;
 	inst->alg.exit = hctr2_exit_tfm;
-	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(xctr_alg);
-	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(xctr_alg);
+	inst->alg.min_keysize = xctr_alg->min_keysize;
+	inst->alg.max_keysize = xctr_alg->max_keysize;
 	inst->alg.ivsize = TWEAK_SIZE;
 
 	inst->free = hctr2_free_instance;