Fix cros lint issues in chromite/scripts.

Fix or disable all cros lint warnings in scripts.

BUG=None
TEST=Ran pylint.

Change-Id: Iedd2f2e361ea82c082f1c95c9054ac15d19193ff
Reviewed-on: https://chromium-review.googlesource.com/190730
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Tested-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Don Garrett <dgarrett@chromium.org>
diff --git a/scripts/cros_extract_deps.py b/scripts/cros_extract_deps.py
index 05cf206..3f4a39a 100644
--- a/scripts/cros_extract_deps.py
+++ b/scripts/cros_extract_deps.py
@@ -3,6 +3,10 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+"""Command to extract the dependancy tree for a given package."""
+
+# pylint: disable=F0401
+# portage is only available inside the chroot.
 import json
 import portage
 from parallel_emerge import DepGraphGenerator
@@ -10,8 +14,9 @@
 from chromite.lib import cros_build_lib
 
 def FlattenDepTree(deptree, pkgtable=None, parentcpv=None):
-  """
-  Turn something like this (the parallel_emerge DepsTree format):
+  """Simplify dependency json.
+
+Turn something like this (the parallel_emerge DepsTree format):
 {
   "app-admin/eselect-1.2.9": {
     "action": "merge",