check_ethernet: Remove check for lab machines

The check whether a DUT is a lab machine is now done in the recover_duts
init snippet.

BUG=chromium:881932
TEST=see CL:1217825
CQ-DEPEND=CL:1217825

Change-Id: I843b8dbaab181175efc408c39dbd5daf20b8a30c
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1217723
Reviewed-by: Douglas Anderson <dianders@chromium.org>
1 file changed