Pylint: abide by useless-object-inheritance warnings

Inheriting from object is a remainder of Python 2 habits and is just
clutter in Python 3.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/check-files.py b/tests/scripts/check-files.py
index 16aebb5..65edecc 100755
--- a/tests/scripts/check-files.py
+++ b/tests/scripts/check-files.py
@@ -17,7 +17,7 @@
 import sys
 
 
-class FileIssueTracker(object):
+class FileIssueTracker:
     """Base class for file-wide issue tracking.
 
     To implement a checker that processes a file as a whole, inherit from
@@ -189,7 +189,7 @@
         return False
 
 
-class IntegrityChecker(object):
+class IntegrityChecker:
     """Sanity-check files under the current directory."""
 
     def __init__(self, log_file):