cros lint: fix func/class docstring checker

Recent pylint updates changed the name of the visit methods.
Update the names so we enforce docstring style on these again.

BUG=chromium:1015273
TEST=`cros lint` found broken styles

Change-Id: Ia6cf8fc72030ee7f93d94853829ae1b2312e1974
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1913181
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Andrew Lamb <andrewlamb@chromium.org>
diff --git a/scripts/deploy_chrome_unittest.py b/scripts/deploy_chrome_unittest.py
index a200844..b7f41c8 100644
--- a/scripts/deploy_chrome_unittest.py
+++ b/scripts/deploy_chrome_unittest.py
@@ -216,7 +216,7 @@
 
 
 class TestMountTarget(DeployTest):
-  """ Testing mount and umount command handling. """
+  """Testing mount and umount command handling."""
 
   def testMountTargetUmountFailure(self):
     """Test error being thrown if umount fails.