Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
(This is part of a larger changeset which is intended to reduce diff only,
thus some prototypes were left intact since they will be changed in the
future).
Verified with: md5(1)