vps_is_mounted(): add support for detecting bind mounts

In non-OpenVZ kernel we use MS_BIND to mount VE_PRIVATE to VE_ROOT.
Before this patch it was not detected, so vzctl status was giving
wrong information, and vzctl umount was not working, among the
other things.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
10 files changed