Revert "deploy: Reboot DUT by cold-reset from servo side" am: b61ec9ef15 am: 51e8f5f039

Original change: undetermined

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: If2af1f5ac4c548c8b7f46c47c21a1ba00789d467
diff --git a/site_utils/deployment/prepare/dut.py b/site_utils/deployment/prepare/dut.py
index 7ee0c3e..d49d9f1 100644
--- a/site_utils/deployment/prepare/dut.py
+++ b/site_utils/deployment/prepare/dut.py
@@ -13,7 +13,6 @@
 from __future__ import print_function
 
 import contextlib
-import six
 import time
 
 import common
@@ -462,10 +461,10 @@
     _check_firmware_update_result(host, fw_update_log)
 
     try:
-        try_reset_by_servo(host)
+        host.reboot()
     except Exception as e:
         logging.debug('Failed to reboot the DUT after update firmware; %s', e)
-        raise Exception('Failed to reboot the DUT after update firmware')
+        try_reset_by_servo(host)
 
     # Once we confirmed DUT can boot from new firmware, get us out of
     # dev-mode and clear GBB flags.  GBB flags are non-zero because