Witness patch

[John Baldwin]

This patch forces witness to complain if any mutex is held when Giant is 
locked to enforce Giant being the first mutex in the lock order.  This might 
help track down some of the network LORs being reported recently.

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

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