crypto: skcipher - pass instance to crypto_grab_skcipher()

Initializing a crypto_skcipher_spawn currently requires:

1. Set spawn->base.inst to point to the instance.
2. Call crypto_grab_skcipher().

But there's no reason for these steps to be separate, and in fact this
unneeded complication has caused at least one bug, the one fixed by
commit 6db4341017 ("crypto: adiantum - initialize crypto_spawn::inst")

So just make crypto_grab_skcipher() take the instance as an argument.

To keep the function calls from getting too unwieldy due to this extra
argument, also introduce a 'mask' variable into the affected places
which weren't already using one.

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

crypto/ctr.c

@@ -286,8 +286,8 @@ static int crypto_rfc3686_create(struct crypto_template *tmpl,
 
 	spawn = skcipher_instance_ctx(inst);
 
-	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
-	err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
+	err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst),
+				   cipher_name, 0, mask);
 	if (err)
 		goto err_free_inst;