Fix the status of an encrypted chroot reported by edit-chroot
Fix the status of an encrypted chroot reported by edit-chroot

* Determine whether it's locked or not by checking /var/run/crouton/... is a mount point or not.
* Fixes #1798

elkangaroo/chroagh,elkangaroo/chroagh,elkangaroo/chroagh,elkangaroo/chroagh,elkangaroo/chroagh,elkangaroo/chroagh