crypto: talitos/hash - prepare SEC1 descriptor chaining, remove additional descriptor

crypto: talitos/hash - prepare SEC1 descriptor chaining, remove additional descriptor

Currently, when SEC1 has buffered data (nbuf != 0), the ahash code
creates an additional descriptor on the fly inside
common_nonsnoop_hash() to handle the remainder of the data. This
approach is incompatible with the arbitrary-length descriptor chaining
that follows.

Remove the "additional descriptor" logic from common_nonsnoop_hash()
and common_nonsnoop_hash_unmap().

Also remove the nbytes adjustment for SEC1 in ahash_edesc_alloc()
that subtracted nbuf.

Cc: stable@vger.kernel.org
Signed-off-by: Paul Louvel <paul.louvel@bootlin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>