vzctl: report CT config saving error

The return code from write_conf() was ignored, therefore
even in case of some error we were still getting the message

	Saved parameters for CT NNN

and 0 exit code from vzctl.

Fix that, and introduce yet another exit code (139) for this particular
error. Number 139 is chosen for compatibility with Parallels Containers.

Man page is updated accordingly.

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