vzctl chkpnt: create dumpdir if not exist

Among the other things, it fixes the vzctl snapshot case:

...
Setting up checkpoint...
Can not create dump file /vz/private/190/dump/{beb0ca0d-4f27-4414-a7be-78e697a7311c}: No such file or directory
Checkpointing failed
...

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
1 file changed