finally silence that good ol appmenu error in linux

src/Avalonia.Base/Logging/LogArea.cs

@@ -39,5 +39,10 @@ namespace Avalonia.Logging
         /// The log event comes from Win32Platform.
         /// </summary>
         public const string Win32Platform = nameof(Win32Platform);
+        
+        /// <summary>
+        /// The log event comes from Win32Platform.
+        /// </summary>
+        public const string X11Platform = nameof(X11Platform);
     }
 }

src/Avalonia.FreeDesktop/DBusMenuExporter.cs

@@ -85,7 +85,9 @@ namespace Avalonia.FreeDesktop
                 }
                 catch (Exception e)
                 {
-                    Console.Error.WriteLine(e);
+                    Logging.Logger.TryGet(Logging.LogEventLevel.Error, Logging.LogArea.X11Platform)
+                        ?.Log(this, e.Message);
+
                     // It's not really important if this code succeeds,
                     // and it's not important to know if it succeeds
                     // since even if we register the window it's not guaranteed that