MFC:	sys/kern/vfs_subr.c	1.680,1.681
MFC:	sys/kern/vfs_subr.c	1.680,1.681

Add a bandaid to avoid a deadlock in a situation, when we are trying to suspend
a file system, but need to obtain a vnode. We may not be able to do it, because
all vnodes could be already in use and other processes cannot release them,
because they are waiting in "suspfs" state.

In such situation, we allow to allocate a vnode anyway.

This is a temporary fix - there is no backpressure to free vnodes allocated in
those circumstances.

Reviewed by:	tegge

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase