Hash import and export was saving and restoring the wrong context
and therefore disabled. Fix it by restoring intermediate digest
and additional state needed.

The hash and mac transform now pass testmgr partial hash tests.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>