docs/107924: [usb67] usbd(8) does not call detach

[gavin at FreeBSD.org]

Synopsis: [usb67] usbd(8) does not call detach

Responsible-Changed-From-To: freebsd-usb->freebsd-docs
Responsible-Changed-By: gavin
Responsible-Changed-When: Sun Nov 8 16:11:48 UTC 2009
Responsible-Changed-Why: 
This PR is actually only relevent for 6.x, as usbd was replaced in 7.x.
Because of that, I can't see this problem being fixed in 6.x alone -
so pass over to doc team to document as a bug instead.

http://www.freebsd.org/cgi/query-pr.cgi?pr=107924