update with newer coding style

synapse/handlers/e2e_keys.py

@@ -851,7 +851,7 @@ class E2eKeysHandler(object):
                 user_id, signed_users
             )
 
-        defer.returnValue({"failures": failures})
+        return {"failures": failures}
 
     @defer.inlineCallbacks
     def _get_e2e_cross_signing_verify_key(self, user_id, key_type, from_user_id=None):

synapse/rest/client/v2_alpha/keys.py

@@ -274,7 +274,7 @@ class SigningKeyUploadServlet(RestServlet):
         )
 
         result = yield self.e2e_keys_handler.upload_signing_keys_for_user(user_id, body)
-        return (200, result)
+        return 200, result
 
 
 class SignaturesUploadServlet(RestServlet):
@@ -324,7 +324,7 @@ class SignaturesUploadServlet(RestServlet):
         result = yield self.e2e_keys_handler.upload_signatures_for_device_keys(
             user_id, body
         )
-        defer.returnValue((200, result))
+        return 200, result
 
 
 def register_servlets(hs, http_server):