Fix lints

synapse/handlers/sliding_sync.py

@@ -226,6 +226,7 @@ class SlidingSyncHandler:
     def __init__(self, hs: "HomeServer"):
         self.clock = hs.get_clock()
         self.store = hs.get_datastores().main
+        self.storage_controllers = hs.get_storage_controllers()
         self.auth_blocking = hs.get_auth_blocking()
         self.notifier = hs.get_notifier()
         self.event_sources = hs.get_event_sources()