crypto: null - Get rid of crypto_{get,put}_default_null_skcipher2()

Since commit 499a66e6b6 ("crypto: null - Remove default null
blkcipher"), crypto_get_default_null_skcipher2() and
crypto_put_default_null_skcipher2() are the same as their non-2
equivalents.  So switch callers of the "2" versions over to the original
versions and remove the "2" versions.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/authencesn.c

@@ -352,7 +352,7 @@ static int crypto_authenc_esn_init_tfm(struct crypto_aead *tfm)
 	if (IS_ERR(enc))
 		goto err_free_ahash;
 
-	null = crypto_get_default_null_skcipher2();
+	null = crypto_get_default_null_skcipher();
 	err = PTR_ERR(null);
 	if (IS_ERR(null))
 		goto err_free_skcipher;
@@ -389,7 +389,7 @@ static void crypto_authenc_esn_exit_tfm(struct crypto_aead *tfm)
 
 	crypto_free_ahash(ctx->auth);
 	crypto_free_skcipher(ctx->enc);
-	crypto_put_default_null_skcipher2();
+	crypto_put_default_null_skcipher();
 }
 
 static void crypto_authenc_esn_free(struct aead_instance *inst)