Fix TODO by removing use of getwd() in nacl-spawn

Fix TODO by removing use of getwd() in nacl-spawn

This also fixes the build which is currently broken
for glibc due to warning about use of getwd() combined
with recent addition of -Werror.

BUG= https://code.google.com/p/naclports/issues/detail?id=109
TEST= run devenv locally

Committed: https://chromium.googlesource.com/external/naclports/+/94aa2ba63679bca1404db21f45cd7febe05ea817

[Sam Clegg, 2014-12-11 21:02:58]

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

[binji, 2014-12-11 23:19:57]

https://codereview.chromium.org/796123002/diff/1/ports/nacl-spawn/nacl_spawn.cc
File ports/nacl-spawn/nacl_spawn.cc (left):

https://codereview.chromium.org/796123002/diff/1/ports/nacl-spawn/nacl_spawn....
ports/nacl-spawn/nacl_spawn.cc:58: //
https://code.google.com/p/naclports/issues/detail?id=109
reference this bug?

[Sam Clegg, 2014-12-11 23:22:22]

Committed patchset #1 (id:1) manually as
94aa2ba63679bca1404db21f45cd7febe05ea817 (tree was closed).