[autotest] Fix reference to get_failure_count()

BUG=chromium:736454
TEST=None

Change-Id: I621fe73e46d6dece521740a931462b0bf647ae67
Reviewed-on: https://chromium-review.googlesource.com/546601
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
diff --git a/site_utils/gs_offloader.py b/site_utils/gs_offloader.py
index 846eb6f..07e7fbd 100755
--- a/site_utils/gs_offloader.py
+++ b/site_utils/gs_offloader.py
@@ -955,7 +955,7 @@
         We mark them as uploaded as we won't try to offload them any more.
         """
         for job in self._open_jobs.values():
-            if job.get_failure_count() >= self._offload_count_limit:
+            if job.offload_count >= self._offload_count_limit:
                 _mark_uploaded(job.dirname)