crypto: chelsio - fix writing tfm flags to wrong place

The chelsio crypto driver is casting 'struct crypto_aead' directly to
'struct crypto_tfm', which is incorrect because the crypto_tfm isn't the
first field of 'struct crypto_aead'.  Consequently, the calls to
crypto_tfm_set_flags() are modifying some other field in the struct.

Also, the driver is setting CRYPTO_TFM_RES_BAD_KEY_LEN in
->setauthsize(), not just in ->setkey().  This is incorrect since this
flag is for bad key lengths, not for bad authentication tag lengths.

Fix these bugs by removing the broken crypto_tfm_set_flags() calls from
->setauthsize() and by fixing them in ->setkey().

Fixes: 324429d7 ("chcr: Support for Chelsio's Crypto Hardware")
Cc: <stable@vger.kernel.org> # v4.9+
Cc: Atul Gupta <atul.gupta@chelsio.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>