[Fedora-livecd-list] [PATCH] Fix cleanup on an error case

If we get an error when installing packages after yum has set up file logging, the unmount (and then losetup -d) can fail. This makes it so that we don't set up the yum file logger; it doesn't really buy us anything and closing it in the error case is nearly impossible with the way python's logging API works. Also, don't create a directory that we're never using. Jeremy