mdadm was updated for 12.1 to fix:
- udev-rules.fix: make sure systemd doesn't try
to mount array before it is fully assembled.
(bnc#752869)

- boot.md/mkinitrd-boot.sh: complete any incremental
assembly before attempting to assemble arrays.
If incremental assembly has partialy assembled
degraded arrays, now is the time to start them going.
(bnc#752869)