kern/102766: geom panics when devices go away

[Pawel Jakub Dawidek]

Synopsis: geom panics when devices go away

Responsible-Changed-From-To: freebsd-bugs->pjd
Responsible-Changed-By: pjd
Responsible-Changed-When: Sat Sep 2 10:23:22 UTC 2006
Responsible-Changed-Why: 
Take this PR. I still think such situations should be handled in
GEOM, not in every single GEOM class. ehh.

http://www.freebsd.org/cgi/query-pr.cgi?pr=102766