vswap: set secondary UBCs if unset

Apparently, if some UBC parameters are not set in VSwap mode,
it makes sense to set those implicitly, based on 'ram' and 'swap'.

	lockedpages	= ram
	oomguarpages	= ram
	vmguarpages	= ram + swap

Also, if vm_overcommit is set:

	privvmpages	= (ram + swap) * vm_overcommit

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