mark_image_bootable: downgrade warning to info

It's not an error condition, don't raise a warning.

BUG=None
TEST=build_image

Change-Id: I9844e16d7abc2496d2115295119f3646982bd948
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/2164209
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Nicolas Norvez <norvez@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
1 file changed