setup_board: use --one-file-system when board dirs

In case the dir happens to have bind mounts (like /dev), make sure we
don't descend into there.

BUG=None
TEST=None

Change-Id: I0b9afd96a4e69c1cc1c9c165a7aa45c53522968c
Reviewed-on: https://chromium-review.googlesource.com/180103
Reviewed-by: David James <davidjames@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed