nebraska: Set noupdate status correctly.

I was setting noupdate in the wrong place. nebraska now responds
correctly to update requests for which no update is available.

BUG=chromium:892450
TEST=Attempt an update with no payloads more recent than the current
installed version on a test device.

Change-Id: If8c3bc9f2d68c69b6700c242f578ddeebd2e59fa
Reviewed-on: https://chromium-review.googlesource.com/1333935
Commit-Ready: Colin Howes <chowes@google.com>
Tested-by: Colin Howes <chowes@google.com>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
1 file changed