Race condition in shlock.c (time window between ValidLock and unlink)

[Katsuhiro Kondou]

In article <ylelbse6ey.fsf at windlord.stanford.edu>,
	Russ Allbery <rra at stanford.edu> wrote;

} circumstances.  So yeah, I vote for just documenting the limitation.

Just noted in BUGS.  Please correct if the wording is
incorrect(including English grammer).
-- 
Katsuhiro Kondou