bisect-kit: fix pylint warnings

Follow chromite's new pylint rules. This CL fixes the trivial ones. More
fixes will come later.

BUG=None
TEST=cros lint

Change-Id: I18bfce6f8cb43bf29ebc3d5af1c5604ecdf50d49
Reviewed-on: https://chromium-review.googlesource.com/1772797
Tested-by: Kuang-che Wu <kcwu@chromium.org>
Commit-Ready: Kuang-che Wu <kcwu@chromium.org>
Commit-Ready: Zheng-Jie Chang <zjchang@google.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Kuang-che Wu <kcwu@chromium.org>
Reviewed-by: Zheng-Jie Chang <zjchang@google.com>
diff --git a/bisect_kit/cli.py b/bisect_kit/cli.py
index ea2550b..d397272 100644
--- a/bisect_kit/cli.py
+++ b/bisect_kit/cli.py
@@ -876,10 +876,10 @@
       description = self.domain_cls.help
     else:
       description = 'Bisector for %s' % self.domain_cls.__name__
-    description += textwrap.dedent('''
+    description += textwrap.dedent("""
         When running switcher and evaluator, it will set BISECT_REV environment
         variable, indicates current rev to switch/evaluate.
-    ''')
+    """)
 
     parser = argparse.ArgumentParser(
         prog=prog,
@@ -905,7 +905,7 @@
         'init',
         help='Initializes bisect session',
         formatter_class=argparse.RawDescriptionHelpFormatter,
-        description=textwrap.dedent('''
+        description=textwrap.dedent("""
           Besides arguments for 'init' command, you also need to set 'switch'
           and 'eval' command line via 'config' command.
             $ bisector config switch <switch command and arguments>
@@ -913,7 +913,7 @@
 
           The value of --noisy and --confidence could be changed by 'config'
           command after 'init' as well.
-        '''))
+        """))
     parser_init.add_argument(
         '--old',
         required=True,
@@ -965,7 +965,7 @@
         'run',
         help='Performs bisection',
         formatter_class=argparse.RawDescriptionHelpFormatter,
-        description=textwrap.dedent('''
+        description=textwrap.dedent("""
         This command does switch and eval to determine candidates having old or
         new behavior.
 
@@ -981,7 +981,7 @@
 
           Switch and run version "2.13" and "2.14" and then stop.
           $ %(prog)s 2.13 2.14
-        '''))
+        """))
     parser_run.add_argument(
         '-1', '--once', action='store_true', help='Only run one step')
     parser_run.add_argument(