Bind mounts can fail to be properly reconnected when PATH_CONNECT is
specified. Ensure that when PATH_CONNECT is specified the path has
a root.

BugLink: http://bugs.launchpad.net/bugs/1319984Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>