tools/battor_agent: Fix unit test compile warnings on other platforms

tools/battor_agent: Fix unit test compile warnings on other platforms

These tests were causing compile warnings on platforms other than Linux.
Now that I'm trying to get the battor_agent tests on the waterfall, this
is problematic.

TBR=zhenw@chromium.org

Committed: https://crrev.com/057026e9c41fb67cdd2998a4697b1764236c7cc5
Cr-Commit-Position: refs/heads/master@{#371516}

[charliea (OOO until 10-5), 2016-01-26 15:14:55]

The CQ bit was checked by charliea@chromium.org

[commit-bot: I haz the power, 2016-01-26 15:15:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1634933005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1634933005/1

[commit-bot: I haz the power, 2016-01-26 15:34:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-01-26 15:35:28]

Description was changed from

==========
tools/battor_agent: Fix unit test compile warnings on other platforms

These tests were causing compile warnings on platforms other than Linux.
Now that I'm trying to get the battor_agent tests on the waterfall, this
is problematic.

TBR=zhenw@chromium.org
==========

to

==========
tools/battor_agent: Fix unit test compile warnings on other platforms

These tests were causing compile warnings on platforms other than Linux.
Now that I'm trying to get the battor_agent tests on the waterfall, this
is problematic.

TBR=zhenw@chromium.org

Committed: https://crrev.com/057026e9c41fb67cdd2998a4697b1764236c7cc5
Cr-Commit-Position: refs/heads/master@{#371516}
==========

[commit-bot: I haz the power, 2016-01-26 15:35:28]

Patchset 1 (id:??) landed as
https://crrev.com/057026e9c41fb67cdd2998a4697b1764236c7cc5
Cr-Commit-Position: refs/heads/master@{#371516}