K 10
svn:author
V 8
hselasky
K 8
svn:date
V 27
2011-10-10T15:54:44.726587Z
K 7
svn:log
V 246
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

END