Fix a couple minor typos in auto_bisect.

Fix a couple minor typos in auto_bisect.

I just discovered a source code spell checker tool called `codespell`.

BUG=

Committed: https://crrev.com/1f7e73b28b1651670c24e15124e35a66b0ab64c9
Cr-Commit-Position: refs/heads/master@{#316657}

[qyearsley, 2015-02-12 22:06:40]

qyearsley@chromium.org changed reviewers:
+ robertocn@chromium.org

[RobertoCN, 2015-02-12 22:25:45]

On 2015/02/12 22:14:00, qyearsley wrote:

LGTM

[qyearsley, 2015-02-13 06:52:10]

The CQ bit was checked by qyearsley@chromium.org

[commit-bot: I haz the power, 2015-02-13 06:52:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/925703002/20001

[commit-bot: I haz the power, 2015-02-13 06:52:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-02-13 06:52:24]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[qyearsley, 2015-02-13 20:57:21]

qyearsley@chromium.org changed reviewers:
+ prasadv@chromium.org

[qyearsley, 2015-02-13 20:57:43]

+ prasadv

(Needs committer lgtm before submit)

[prasadv, 2015-02-17 19:24:21]

lgtm

[qyearsley, 2015-02-17 21:11:57]

The CQ bit was checked by qyearsley@chromium.org

[commit-bot: I haz the power, 2015-02-17 21:13:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/925703002/20001

[commit-bot: I haz the power, 2015-02-17 21:35:43]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-17 21:36:08]

Patchset 2 (id:??) landed as
https://crrev.com/1f7e73b28b1651670c24e15124e35a66b0ab64c9
Cr-Commit-Position: refs/heads/master@{#316657}