[autotest] Remove unused variable

BUG=chromium:672348
TEST=None

Change-Id: I0033c3e76638bd90095ed008252247102fa4c1dd
Reviewed-on: https://chromium-review.googlesource.com/560658
Commit-Ready: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
diff --git a/site_utils/run_suite.py b/site_utils/run_suite.py
index f18d9eb..63feb1b 100755
--- a/site_utils/run_suite.py
+++ b/site_utils/run_suite.py
@@ -1674,7 +1674,6 @@
 
     @return SuiteResult of suite job.
     """
-    code = RETURN_CODES.OK
     output_dict = {}
     rpc_helper = diagnosis_utils.RPCHelper(afe)
     instance_server = afe.server