crypto: scatterwalk - Add no-copy support to copychunks

crypto: scatterwalk - Add no-copy support to copychunks

Orabug: 25243093

The function ablkcipher_done_slow is pretty much identical to
scatterwalk_copychunks except that it doesn't actually copy as
the processing hasn't been completed yet.

This patch allows scatterwalk_copychunks to be used in this case
by specifying out == 2.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit 85eccddee401ae81067e763516889780b5545160)
Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>