[autotest] Fix couple bugs in gs_offloader

BUG=b:62157091
TEST=unittest, run in a drone

Change-Id: I1f39a730c42ccb62840a4a041afeb472b43cdf46
Reviewed-on: https://chromium-review.googlesource.com/517763
Commit-Ready: Dan Shi <dshi@google.com>
Tested-by: Dan Shi <dshi@google.com>
Reviewed-by: Paul Hobbs <phobbs@google.com>
diff --git a/site_utils/gs_offloader.py b/site_utils/gs_offloader.py
index d38277d..02efc43 100755
--- a/site_utils/gs_offloader.py
+++ b/site_utils/gs_offloader.py
@@ -179,7 +179,10 @@
         # There could be multiple hosts in the job directory, use the first one
         # available.
         for host in glob.glob(os.path.join(dir_entry, '*')):
-            keyval = models.test.parse_job_keyval(host)
+            try:
+                keyval = models.test.parse_job_keyval(host)
+            except ValueError:
+                continue
             build = keyval.get('build')
             if build:
                 try:
@@ -892,7 +895,7 @@
         We mark them as uploaded as we won't try to offload them any more.
         """
         for job in self._open_jobs.values():
-            if job.offload_count >= self._offload_count_limit:
+            if job.get_failure_count() >= self._offload_count_limit:
                 _mark_uploaded(job.dirname)