MIPS: remove immediate constraint within CompareAndSwap.

MIPS: remove immediate constraint within CompareAndSwap.

Improper use of immediate constraint is slightly non-optimal
with gcc/gnu-as but may cause breakage with clang.

BUG=

Committed: https://crrev.com/8bd6f985f24f3ab29fbfd325e678121f33dd3518
Cr-Commit-Position: refs/heads/master@{#313302}

[gordanac, 2015-01-26 14:20:04]

gordana.cmiljanovic@imgtec.com changed reviewers:
+ agl@chromium.org

[gordanac, 2015-01-26 14:20:23]

Please take a look.

[agl, 2015-01-26 21:28:18]

The CQ bit was checked by agl@chromium.org

[agl, 2015-01-26 21:28:19]

lgtm

[commit-bot: I haz the power, 2015-01-26 21:29:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/872393003/1

[commit-bot: I haz the power, 2015-01-26 21:37:24]

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

[commit-bot: I haz the power, 2015-01-26 21:37:25]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[gordanac, 2015-01-27 10:22:10]

gordana.cmiljanovic@imgtec.com changed reviewers:
+ thakis@chromium.org

[gordanac, 2015-01-27 11:34:19]

+thakis 
as base OWNER approval is needed.

[Nico, 2015-01-27 17:15:43]

rs-lgtm

[Nico, 2015-01-27 17:15:48]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2015-01-27 17:16:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/872393003/1

[commit-bot: I haz the power, 2015-01-27 17:17:19]

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

[commit-bot: I haz the power, 2015-01-27 17:17:20]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[agl, 2015-01-27 17:49:31]

The CQ bit was checked by agl@chromium.org

[commit-bot: I haz the power, 2015-01-27 17:49:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/872393003/1

[commit-bot: I haz the power, 2015-01-27 17:51:14]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-27 17:52:21]

Patchset 1 (id:??) landed as
https://crrev.com/8bd6f985f24f3ab29fbfd325e678121f33dd3518
Cr-Commit-Position: refs/heads/master@{#313302}