heads up: rename fixed

[David Holland <dholland-current%netbsd.org@localhost>]

The long-awaited ufs_rename fixes are in. Let me know if this causes
anything else to blow up.

This fixes rename for vanilla ffs and ffs+wapbl. It should also mostly
fix rename for lfs, but there seem to also be some lfs issues involved
there. ext2fs, despite being attached to ufs, has its own largely c&p
copy of rename and will need its own fix. Hopefully this can be a c&p
fix.

Other fses with their own rename implementations whose locking is
clearly wrong include tmpfs, msdosfs, udf, and nilfs.

-- 
David A. Holland
dholland%netbsd.org@localhost