/storage will be unmounted by systemd-shutdown, like /flash.
As the squashfs root has several symlinks to /storage it
should not be unmounted during the normal shutdown process.
This prevents the symlinked files/directories vanishing too early
and also removes the "unmount /storage failed" messages when
netbooting.
Signed-off-by: Matthias Reichl <hias@horus.com>
