Fix compiler warning in vboot_reference

BUG=none
TEST=none

Change-Id: I60089b4bfb5f4ba2f0df66f335794b3fed1495f3
Reviewed-on: http://gerrit.chromium.org/gerrit/3787
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Tested-by: Randall Spangler <rspangler@chromium.org>
1 file changed