env_set_vcpus(): fix error return code

In case we fail to set VCPUs, return proper error code since it is used
as an exit code by vzctl. Here's one of the code propagation paths:

main()
  run_action()
    start()
      vps_start()
        vps_start_custom()
          vps_setup_res()
            vps_set_cpu()
              env_set_vcpus()

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