[illumos-Developer] webrev: ZFS FRMI scheme fix

[Garrett D'Amore]

http://mexico.purplecow.org/gdamore/webrev/zfs-fmri/

This fixes an FMRI scheme bug, which fails to properly consider that
hot-spares are vdevs that participate within a ZFS pool.  This failure
means that a failing hot spare might not be noticed within the zpool.

(A separate bug, to monitor zpool vdevs via an FMA plugin we wrote, will
be coming along soon.  That plugin depends upon this fix.)

We've been using this change as part of NexentaStor 3.0.3 and 3.0.4 for
about 5 months or so now, so its pretty well tested.

Please let me know if you have any feedback.

	- Garrett