linux: ignore warnings about unused results in third-party code

This warning is frequent in our build logs across multiple third-party
modules.  It seems clear to me that upstreams don't see it
in their builds.

Review URL: http://codereview.chromium.org/7465052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@94185 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed