Attempting to use the sha1 digest for openssh via openssl reveals that
the result from the hash is wrong: this happens when we export the
state from one socket and import it into another via calling accept().

The reason for this is because the operation is reset to "initial block"
state, whereas we may be past the first fragment of data to be hashed.

Arrange for the operation code to avoid the initialisation of the state,
thereby preserving the imported state.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>