Fix telemetry error reason string formatting.

Currently failure reasons are not interpolated. Sample:
('Telemetry test: %s failed.', 'webgl_conformance')

Also silence some pylint warnings.

BUG=None.
TEST=None.

Change-Id: I3e59bf56fb5f3bf959ecaf63553fb5cd384258d0
Reviewed-on: https://chromium-review.googlesource.com/199647
Tested-by: Ilja Friedel <ihf@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Ilja Friedel <ihf@chromium.org>
diff --git a/server/cros/telemetry_runner.py b/server/cros/telemetry_runner.py
index 1c26f57..8bd89da 100644
--- a/server/cros/telemetry_runner.py
+++ b/server/cros/telemetry_runner.py
@@ -8,7 +8,6 @@
 import re
 import StringIO
 
-import common
 from autotest_lib.client.common_lib import error, utils
 from autotest_lib.client.common_lib.cros import dev_server
 
@@ -212,7 +211,8 @@
                       locally.
         """
         self._host = host
-
+        self._devserver = None
+        self._telemetry_path = None
         # TODO (llozano crbug.com/324964). Remove conditional code.
         # Use a class hierarchy instead.
         if local:
@@ -354,8 +354,7 @@
         telemetry_script = os.path.join(self._telemetry_path, script)
         result = self._run_telemetry(telemetry_script, test)
         if result.status is FAILED_STATUS:
-            raise error.TestFail('Telemetry test: %s failed.',
-                                 test)
+            raise error.TestFail('Telemetry test %s failed.' % test)
         return result