imsm: FIX: Remove single map state limitation in getinfo

imsm: FIX: Remove single map state limitation in getinfo

It can occur that degradation during migration occurs on disks that are not
present in both maps /e.g. degradation on just added disk during OLCE/.
This can cause that maps will be in different states (one will be in degraded
and second in normal state). In such situation getinfo_super_imsm_volume()
will not return migration information.

Remove single state limitation in both maps to allow migration information
retrieving.

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>