vboot: fix compiling with DEBUG=1

If FOR_TEST is defined, 2common.h defines VB2_DEBUG() to be printf();
it should include stdio.h as well.

The HOSTLIB extern linktest links against the vboot1 stub functions,
but not the vboot2 stub functions, so it couldn't find vb2ex_printf().

BUG=chromium:682058
BRANCH=none
TEST=DEBUG=1 make runtests; DEBUG=1 emerge-reef vboot_reference depthcharge

Change-Id: Ibf981a70ca4087ce3d86b02d76e03063b2cfc9e5
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/429310
Commit-Ready: Shelley Chen <shchen@chromium.org>
Reviewed-by: Shelley Chen <shchen@chromium.org>
2 files changed