Hans Petter Selasky f6c6639af8 Bugfix: The ucom detach function is sometimes called on zeroed structures.
Check for this case and just return, so that the UCOM unit number zero is
not accidentially freed.

Submitted by:	Danish FreeBSD user at EuroBSDcon 2011
MFC after:	3 days
2011-10-10 15:54:44 +00:00
..
2011-08-20 16:21:40 +00:00
2011-06-24 19:32:29 +00:00
2011-06-24 19:32:29 +00:00