I think, it's better if we still restore the original vvar
as some code may expect vma to be there or may dereference
pointer there.
E.g., if we checkpointed task while it was on vdso page,
it'll dereference pointer to vvar. Better keep it in vmas.

So, the original code deleted it becase it was proxy_vvar_marked,
which I think is misnaming problem.
Having two vvar addresses named rt_ and orig_ describes what to
do with them on dump.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>