Linux Sandbox: setuid sandbox initialization cleanup.

Small cleanup of the setuid sandbox initialization. This is in
preparation for the introduction of the USER_NS sandbox.

BUG=312380
NOTRY=true

Review URL: https://codereview.chromium.org/184393006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254560 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed