helper functions to determine the list of devices in an array,
etc.
Signed-off-by: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
I forgot to check in this helper script, similar to the one for IMSM.
It is needed by tests/10ddf-create-fail-rebuild.
Signed-off-by: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>