2lib: Prevent overwriting the value of fw_vboot2

BUG=b:305868231
TEST=crossystem fw_vboot2

Change-Id: Iedc71405d52eb8d1580ce6754c5b688ff19ef56c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4943296
Reviewed-by: Ivan Chen <yulunchen@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
Commit-Queue: Yi Chou <yich@google.com>
Tested-by: Yi Chou <yich@google.com>
1 file changed