mount: check bondaries in mount_resolve_path

The current code think that /vz/lxc/centos-6-x86_64-root is
in /vz/lxc/centos-6-x86_64.

If the path is not equal to mountpoint, we need to check, that
path contains a slash after mountpoint.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

mount.c

@@ -158,6 +158,8 @@ static struct mount_info *mount_resolve_path(const char *path)
 
 			if (strncmp(c->mountpoint, path, min(n, pathlen)))
 				continue;
+			if (n < pathlen && path[n] != '/')
+				continue;
 
 			m = c;
 			break;