[NaCl SDK]: nacl_io: add nacl_io_uninit function.

[NaCl SDK]: nacl_io: add nacl_io_uninit function.

Call this function on program shut down to allow
nacl_io to free its resources.  This fixes
all the "potential" leak reported by valgrind
--leak-check=full

Committed: https://crrev.com/e3c6d9defedfec359fc3d7c69fd63fa36035e722
Cr-Commit-Position: refs/heads/master@{#296720}

[Sam Clegg, 2014-09-24 23:43:22]

sbc@chromium.org changed reviewers:
+ binji@chromium.org

[Sam Clegg, 2014-09-25 01:20:07]

Patchset #3 (id:40001) has been deleted

[Sam Clegg, 2014-09-25 01:20:27]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2014-09-25 01:22:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/601963002/20001

[commit-bot: I haz the power, 2014-09-25 01:22:09]

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

[commit-bot: I haz the power, 2014-09-25 01:22:10]

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 or
a provisional 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.

[binji, 2014-09-25 01:30:31]

lgtm

[Sam Clegg, 2014-09-25 15:27:54]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2014-09-25 15:28:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/601963002/20001

[commit-bot: I haz the power, 2014-09-25 16:24:00]

Committed patchset #2 (id:20001) as 947cc0109fac6144a6463fbedfa353d05c5cb029

[commit-bot: I haz the power, 2014-09-25 16:24:35]

Patchset 2 (id:??) landed as
https://crrev.com/e3c6d9defedfec359fc3d7c69fd63fa36035e722
Cr-Commit-Position: refs/heads/master@{#296720}