crypto: remove propagation of CRYPTO_TFM_RES_* flags

The CRYPTO_TFM_RES_* flags were apparently meant as a way to make the
->setkey() functions provide more information about errors.  But these
flags weren't actually being used or tested, and in many cases they
weren't being set correctly anyway.  So they've now been removed.

Also, if someone ever actually needs to start better distinguishing
->setkey() errors (which is somewhat unlikely, as this has been unneeded
for a long time), we'd be much better off just defining different return
values, like -EINVAL if the key is invalid for the algorithm vs.
-EKEYREJECTED if the key was rejected by a policy like "no weak keys".
That would be much simpler, less error-prone, and easier to test.

So just remove CRYPTO_TFM_RES_MASK and all the unneeded logic that
propagates these flags around.

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

arch/x86/crypto/ghash-clmulni-intel_glue.c

@@ -255,16 +255,11 @@ static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 {
 	struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 	struct crypto_ahash *child = &ctx->cryptd_tfm->base;
-	int err;
 
 	crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 	crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 			       & CRYPTO_TFM_REQ_MASK);
-	err = crypto_ahash_setkey(child, key, keylen);
-	crypto_ahash_set_flags(tfm, crypto_ahash_get_flags(child)
-			       & CRYPTO_TFM_RES_MASK);
-
-	return err;
+	return crypto_ahash_setkey(child, key, keylen);
 }
 
 static int ghash_async_init_tfm(struct crypto_tfm *tfm)