vnode kernel panic when removed while nfs serves it (well don't do that then)

[Dirk-Willem van Gulik]

Certainly in the class of 'Doctor: If I poke in my eye it hurts; well
don't do that then') -  on FreeBSD -current as of today.

Add /mnt to your exports file on an NFS server; and do:

	mdconfig -a -t vnode some-disk
	mount /dev/md0a /mnt
	killall -1 mountd
..
	let at least one nfs client mount it.
Then do
	umount - /mnt
	mdconfig -d -u 0

First XS by the nfs will panic the machine - the actual stacktrace it self
is too corrupted to see where.

Dw