Replace atoi usage with strtol

When using atoi to convert from string to int, we can not tell when
there is error. Use strtol to properly handle the errors.

BUG=b:320231979
TEST=Unit tests

Change-Id: I0e008f2eddaeb601593ad4e91c8d1fa7beab0cd9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/5211625
Commit-Queue: Baili Deng <bailideng@google.com>
Reviewed-by: Li-Yu Yu <aaronyu@google.com>
Tested-by: chromeos-cop-builder@chromeos-cop.iam.gserviceaccount.com <chromeos-cop-builder@chromeos-cop.iam.gserviceaccount.com>
12 files changed