Add missing $FreeBSD$.
Remove no longer useful (and commented out) debug.
Use a more traditional assertion name.
Don't mix initializers with declarations.
Wrap long lines.
Remove useless assignment.
Remove unneeded vfs_busy(), unneccessary, because vn is locked.
Doc fixes from wblock@ and allanjude@.
10.2 -> 10.1, hopefully.
Doc tweak.