Fix obviously broken error handling.
Fix obviously broken error handling.

R=vadimsh@chromium.org, dnj@chromium.org, estaab@chromium.org, tandrii@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1269593002 .

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go