While they have the same bit representation, the variable was unsigned
so the comparison would always fail, which triggered a compilation
warning.

BUG=

Change-Id: Idbbdb942b71d59f95e65c072dbbfdf31d14eda05
Reviewed-on: https://chromium-review.googlesource.com/303391Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tryjob-Request: Corentin Wallez <cwallez@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>