/etc/peiodic/daily/100.clean-disks cleans out file systems
	that don't have real files in them, like /dev on systems that
	use devfs.

Fix: 

Ok, I fibbed. The patch isn't here, it's in
http://www.FreeBSD.org/cgi/query-pr.cgi?pr=conf/35545, which includes
a path to add an exclude list to 100.clean-disks. That should be
applied, and daily_clean_disks_exclude should be set to /dev on
systems that mount devfs on /dev by default.
How-To-Repeat: 
	devfs doesn't create any problems, but fdesc does. Mount fdesc
	on /dev/fd (which is where most things expect it), and then
	run 100.clean-disks. I get output like so:
	
Cleaning disks:
find: /dev/fd/3/.w3m: No such file or directory
find: /dev/fd/3/.ssh: No such file or directory
find: /dev/fd/3/.ncftp: No such file or directory
find: /dev/fd/3/.saves-18226-: No such file or directory
find: /dev/fd/3/.k5login: No such file or directory
find: /dev/fd/3/.cshrc: No such file or directory
find: /dev/fd/3/.login: No such file or directory
find: /dev/fd/3/.profile: No such file or directory
find: /dev/fd/3/.history: No such file or directory
find: /dev/fd/3/.saves-33368-guru.mired.org: No such file or directory
find: /dev/fd/3: No such file or directory
find: /dev/fd/4/.w3m: No such file or directory
find: /dev/fd/4/.ssh: No such file or directory
find: /dev/fd/4/.ncftp: No such file or directory
find: /dev/fd/4/.saves-18226-: No such file or directory
find: /dev/fd/4/.k5login: No such file or directory
find: /dev/fd/4/.cshrc: No such file or directory
find: /dev/fd/4/.login: No such file or directory
find: /dev/fd/4/.profile: No such file or directory
find: /dev/fd/4/.history: No such file or directory
find: /dev/fd/4/.saves-33368-guru.mired.org: No such file or directory
find: /dev/fd/4: No such file or directory
find: /dev/fd/5: Bad file descriptor