Chane pinning mechanism: Use $rootfs/lxc.hold instead of $rootfs.hold
(in case $rootfs is a mountpoint itself), but delete the file
immediately after creating it (but keep it open). This will keep the
root filesystem busy but does not leave any unnecessary files lying
around.
Signed-off-by: Christian Seiler <christian@iwakd.de>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>