Change for the hobbit client under FreeBSD

Can I request that "fdescfs" is added to the list of file systems that
df doesn't return information on.  I've recently had reason to add
this to a number of hosts and, as it's a pseudo file system that's
always 100%, it then causes a red alert for the disk status on those
hosts.

Either that or a generic change to ignore any mount point that doesn't
have a "/" in it (which should catch any pseudo filesystem).

Patch for the former attached as that bit's easy :)

-- 
Rob MacGregor
      Whoever fights monsters should see to it that in the process he
        doesn't become a monster.                  Friedrich Nietzsche