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>

drivers/crypto/mxs-dcp.c

@@ -492,7 +492,6 @@ static int mxs_dcp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			      unsigned int len)
 {
 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
-	unsigned int ret;
 
 	/*
 	 * AES 128 is supposed by the hardware, store key into temporary
@@ -513,16 +512,7 @@ static int mxs_dcp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	crypto_sync_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK);
 	crypto_sync_skcipher_set_flags(actx->fallback,
 				  tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
-
-	ret = crypto_sync_skcipher_setkey(actx->fallback, key, len);
-	if (!ret)
-		return 0;
-
-	tfm->base.crt_flags &= ~CRYPTO_TFM_RES_MASK;
-	tfm->base.crt_flags |= crypto_sync_skcipher_get_flags(actx->fallback) &
-			       CRYPTO_TFM_RES_MASK;
-
-	return ret;
+	return crypto_sync_skcipher_setkey(actx->fallback, key, len);
 }
 
 static int mxs_dcp_aes_fallback_init_tfm(struct crypto_skcipher *tfm)