Improve the print of listener startup

src/emqx_listeners.erl

@@ -33,9 +33,9 @@ start() ->
 start_listener({Proto, ListenOn, Options}) ->
     case start_listener(Proto, ListenOn, Options) of
         {ok, _} ->
-            io:format("Start mqtt:~s listener on ~s successfully~n", [Proto, format(ListenOn)]);
+            io:format("Start mqtt:~s listener on ~s successfully.~n", [Proto, format(ListenOn)]);
         {error, Reason} ->
-            io:format(standard_error, "Failed to start mqtt:~s listener on ~s - ~p",
+            io:format(standard_error, "Failed to start mqtt:~s listener on ~s - ~p!",
                       [Proto, format(ListenOn), Reason])
     end.
 
@@ -114,9 +114,9 @@ stop() ->
 stop_listener({Proto, ListenOn, Opts}) ->
     case stop_listener(Proto, ListenOn, Opts) of
         ok ->
-            io:format("Stop mqtt:~s listener on ~s successfully~n", [Proto, format(ListenOn)]);
+            io:format("Stop mqtt:~s listener on ~s successfully.~n", [Proto, format(ListenOn)]);
         {error, Reason} ->
-            io:format(standard_error, "Failed to stop mqtt:~s listener on ~s - ~p",
+            io:format(standard_error, "Failed to stop mqtt:~s listener on ~s - ~p.",
                       [Proto, format(ListenOn), Reason])
     end.