make git_cl lint cleanly on mac. I look forward to the day when json can
be assumed to be installed.

R=maruel@chromium.org

Review URL: http://codereview.chromium.org/6771041

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@80209 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/git_cl.py b/git_cl.py
index e7569e2..e22ea6a 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -27,7 +27,7 @@
   except ImportError:
     # Fall back to the packaged version.
     sys.path.append(os.path.join(os.path.dirname(__file__), 'third_party'))
-    import simplejson as json
+    import simplejson as json  # pylint: disable=F0401
 
 
 from third_party import upload