[Fedora-livecd-list] Only lazy unmount if umount doesn't succeed

[Bruno Wolff III]

On Fri, Jul 30, 2010 at 20:44:19 -0700,
  Jasper Hartline <jasper.hartline at gmail.com> wrote:
> Patch for fs.py in git livecd-tools to only lazy unmount if we have to

I'd like to see this go in a bit after alpha in any case. This will help
us notice if something is broken, but is hidden by lazy umounts.
The change should be repeated in both places that do umounts.