[CRYPTO] api: Get rid of flags argument to setkey

Now that the tfm is passed directly to setkey instead of the ctx, we no
longer need to pass the &tfm->crt_flags pointer.

This patch also gets rid of a few unnecessary checks on the key length
for ciphers as the cipher layer guarantees that the key length is within
the bounds specified by the algorithm.

Rather than testing dia_setkey every time, this patch does it only once
during crypto_alloc_tfm.  The redundant check from crypto_digest_setkey
is also removed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/crypto_null.c

diff --git a/crypto/crypto_null.c b/crypto/crypto_null.c
index a0d956b..24dbb5d 100644
--- a/crypto/crypto_null.c
+++ b/crypto/crypto_null.c
@@ -48,7 +48,7 @@
 { }
 
 static int null_setkey(struct crypto_tfm *tfm, const u8 *key,
-		       unsigned int keylen, u32 *flags)
+		       unsigned int keylen)
 { return 0; }
 
 static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)