stable/12->stable/13 can't find boot filesystem

[Walter von Entferndt]

Please look at the ouput of "zpool get bootfs".  It is recommended to 
make use of ZFS boot environments (bectl or beadm) to safely perform 
such updates.  Please also note that you have to update the bootblocks, 
iff you upgrade the zpool (enable new features/historical "version").
-- 
=|o)  "Stell' Dir vor es geht und keiner kriegt's hin." (Wolfgang Neuss)