Failure to remove redirect role when removing btrfs-in-partition pool member via Resize/ReRaid

[phillxnet]

Our strongly discourages btrfs-in-partition capability fails to remove redirect roles in some circumstances. This is not a show-stopper as our focus is almost entirely on whole-disk btrfs; but it would be nice to have a confirmed reproducer for this issue for when there are resources (human) available to investigate further.

Our redirect role enables the use of btrfs-in-partition, and import can add this role to other Pool members when importing a Pool via a whole-disk member. But when removing this same device from the resulting Pool via the Resize/ReRaid we can end up with a defunct redirection to a now non-existent btrfs filesystem in partition (blank partition as the removal completed successfully) . This remaining DB drive state confuses the Web-UI. Work-around is to null the disk role field within the DB (removing the now defunct redirection).