nve locking fixes round 2

[John Baldwin]

Ok, now that the first set of locking overhaul is in the tree, can folks with 
working nve(4) adapters test the patch referenced below and make sure there 
are no regressions.  Having the IFF_UP fiddling turned off may or may not 
help folks getting the TX timeouts as well, btw, so if people are feeling 
brave they can try this patch as well.  Note it is only applicable to recent 
current.

http://www.FreeBSD.org/~jhb/patches/nve_locking.patch

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org