[autotest] Make DUT repair flow not blocked by servo repair failure

TEST=manually make create_healthy_servo raise an exception and confirm
the dut repair flow continues.
BUG=chromium:305022

Change-Id: I40e532dec1a513576a2f7cbcd44902fbcd976215
Reviewed-on: https://chromium-review.googlesource.com/172192
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
Commit-Queue: Fang Deng <fdeng@chromium.org>
Tested-by: Fang Deng <fdeng@chromium.org>
1 file changed