Cut a tie between power_LoadTest and backchannel

power_LoadTest uses backchannel, but also made use of a questionable
backchannel utility function to check whether a network interface is up.
This is the only use of that utility function, and this is a step
towards removing the function from backchannel.

BUG=chrome-os-partner:35127
TEST=Being tested by test owners.
CQ-DEPEND=CL:236942

Change-Id: I812e4edb454216329d1e7b3242723d1d83167c2e
Reviewed-on: https://chromium-review.googlesource.com/238370
Trybot-Ready: Eric Caruso <ejcaruso@chromium.org>
Tested-by: Eric Caruso <ejcaruso@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Tested-by: Christopher Grant <cjgrant@chromium.org>
1 file changed