Fix two minor bugs found by /analyze

Fix two minor bugs found by /analyze

BUG=427616
/analyze pointed out that the loop range-check used the comma operator
when && was probably intended. The bug was harmless, but confusing, so
I fixed it.

/analyze also pointed out that the code was checking data read by a
function and then checking whether the read succeeded. Reversing the
order of the checks has no effect except to get rid of the undefined
behavior.

Committed: https://crrev.com/1fd77f5dac94f7bd887cfee74742e6894f14beac
Cr-Commit-Position: refs/heads/master@{#301691}

[brucedawson, 2014-10-28 00:27:09]

brucedawson@chromium.org changed reviewers:
+ robertshield@chromium.org

[robertshield, 2014-10-28 00:38:32]

The CQ bit was checked by robertshield@chromium.org

[robertshield, 2014-10-28 00:38:33]

lgtm

Ah, good finds, especially the comma operator.

[commit-bot: I haz the power, 2014-10-28 00:41:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/678193003/1

[commit-bot: I haz the power, 2014-10-28 06:45:18]

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

[commit-bot: I haz the power, 2014-10-28 06:45:19]

Exceeded time limit waiting for builds to trigger.

[cpu_(ooo_6.6-7.5), 2014-10-28 19:46:12]

The CQ bit was checked by cpu@chromium.org

[commit-bot: I haz the power, 2014-10-28 19:47:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/678193003/1

[commit-bot: I haz the power, 2014-10-28 19:58:32]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-28 19:59:09]

Patchset 1 (id:??) landed as
https://crrev.com/1fd77f5dac94f7bd887cfee74742e6894f14beac
Cr-Commit-Position: refs/heads/master@{#301691}