cbuildbot: pass in disk layout argument to image_to_vm.sh

It's needed for the amd64-generic-tot-asan-informational builder.

BUG=chromium:697967
TEST=Not sure how to test this buildbot change, but with CL:468370
applied the following buildbot succeeded in the BuildImage stage:

https://uberchromegw.corp.google.com/i/chromiumos.tryserver/builders/tot_asan_informational/builds/28

Change-Id: I46b7f2ccc8a1e98ade2c3dd16e37128265c43a23
Reviewed-on: https://chromium-review.googlesource.com/486248
Commit-Ready: Gurchetan Singh <gurchetansingh@chromium.org>
Tested-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Ilja H. Friedel <ihf@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed