Bug 1616172 - Remove encoding when printing diff in Fluent migration tests r=Pike

Differential Revision: https://phabricator.services.mozilla.com/D63128

--HG--
extra : moz-landing-system : lando

python/l10n/test_fluent_migrations/fmt.py

@@ -55,8 +55,7 @@ def diff_resources(left_path, right_path):
             res = parser.parse(fh.read())
             lines.append(serializer.serialize(res).splitlines(True))
     sys.stdout.writelines(
-        chunk.encode('utf-8')
-        for chunk in unified_diff(lines[0], lines[1], left_path, right_path)
+        chunk for chunk in unified_diff(lines[0], lines[1], left_path, right_path)
     )