futility: Fix build failure by missing struct declaration

The factory branch seem to not always include vb2 structures
so we have to declare directly in futility.h.

BUG=chromium:923331
TEST=make futil -j

Change-Id: I4b4073244b034426544d8f4f1dd79a0c8c36b7e7
Reviewed-on: https://chromium-review.googlesource.com/c/1421579
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Queue: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Trybot-Ready: Hung-Te Lin <hungte@chromium.org>
(cherry picked from commit b861c14e3f19d712f76093309071873a5bef08b3)
Reviewed-on: https://chromium-review.googlesource.com/c/1421584
1 file changed