[NaCl SDK] nacl_io: seperate socket syscalls into thier own directory.

[NaCl SDK] nacl_io: seperate socket syscalls into thier own directory.

This change contains only renames. It allows us to
distingish between socket syscalls and others syscall
overrides, which helps us to identify overrides that
we should be aiming to eliminate.

Committed: https://crrev.com/2fe81bc37a2da88b2fd7cc94360435cb98d16cdf
Cr-Commit-Position: refs/heads/master@{#293840}

[Sam Clegg, 2014-09-08 18:42:08]

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

[binji, 2014-09-08 18:50:52]

lgtm

[Sam Clegg, 2014-09-08 23:17:50]

The CQ bit was checked by sbc@chromium.org

[commit-bot: I haz the power, 2014-09-08 23:21:49]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/sbc@chromium.org/556533002/1

[commit-bot: I haz the power, 2014-09-09 02:54:53]

Committed patchset #1 (id:1) as ea413c1dfd4092df4b6855207a1a655118c1118e

[commit-bot: I haz the power, 2014-09-10 03:49:55]

Patchset 1 (id:??) landed as
https://crrev.com/2fe81bc37a2da88b2fd7cc94360435cb98d16cdf
Cr-Commit-Position: refs/heads/master@{#293840}