fix errors found by dialyzer

apps/emqttd/src/emqttd_bridge_sup.erl

@@ -74,7 +74,7 @@ start_bridge(Node, SubTopic, Options) when is_atom(Node) and is_binary(SubTopic)
 -spec stop_bridge(atom(), binary()) -> {ok, pid()} | ok.
 stop_bridge(Node, SubTopic) ->
     ChildId = bridge_id(Node, SubTopic),
-    case supervisor:terminate_child(ChildId) of
+    case supervisor:terminate_child(?MODULE, ChildId) of
         ok -> 
             supervisor:delete_child(?MODULE, ChildId);
         {error, Reason} ->

apps/emqttd/src/emqttd_event.erl

@@ -114,5 +114,5 @@ payload(connected, Params) ->
     iolist_to_binary(io_lib:format("from: ~s~nprotocol: ~p~nsession: ~s", [From, Proto, Sess]));
 
 payload(disconnected, Reason) ->
-    list_to_binary(io_lib:format(["reason: ~p", Reason])).
+    list_to_binary(io_lib:format("reason: ~p", [Reason])).