We're using Ethereal chroot style on Travis CI.
In that chroot style, `uname -m` reports x86_64 even if we're
bootstrapped with i686 systems.
Some i686 build that employ `uname -m` is failing on Travis CI,
e.g: https://travis-ci.org/void-linux/void-packages/jobs/648010517#L5787
Change `uname` output to make Travis Output meaningful for i686.