crypto: algif_hash - Require setkey before accept(2)

commit 6de62f15b581f920ade22d758f4c338311c2f0d4 upstream.

Hash implementations that require a key may crash if you use
them without setting a key.  This patch adds the necessary checks
so that if you do attempt to use them without a key that we return
-ENOKEY instead of proceeding.

This patch also adds a compatibility path to support old applications
that do acept(2) before setkey.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>