vzcfgvalidate: fix exit code in case validation failed

vzcfgvalidate(8) manual page says exit code of 2 is expected
in case configuration is invalid.

Commit 95b0f03 accidentally broke that functionality, but even
before it the exit code in this case was 1 not 2.

Fix the behavior to comply with the man page.

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