[autotest] Remove failure handling in archive step

Since the archive step is now "true", it will/should never fail.

BUG=chromium:699275
TEST=None

Change-Id: I0465eb87f7d7f5d7d72fc344308db0b1a1dd38d1
Reviewed-on: https://chromium-review.googlesource.com/507019
Commit-Ready: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
diff --git a/scheduler/postjob_task.py b/scheduler/postjob_task.py
index 9438277..60e3b07 100644
--- a/scheduler/postjob_task.py
+++ b/scheduler/postjob_task.py
@@ -381,12 +381,4 @@
 
     def epilog(self):
         super(ArchiveResultsTask, self).epilog()
-        if not self.success and self._paired_with_monitor().has_process():
-            failed_file = os.path.join(self._working_directory(),
-                                       self._ARCHIVING_FAILED_FILE)
-            paired_process = self._paired_with_monitor().get_process()
-            self._drone_manager.write_lines_to_file(
-                    failed_file, ['Archiving failed with exit code %s'
-                                  % self.monitor.exit_code()],
-                    paired_with_process=paired_process)
         self._set_all_statuses(self._final_status())