Minor app builder fix

src/Avalonia.Controls/AppBuilder.cs

@@ -151,7 +151,7 @@ namespace Avalonia
             }
 
             throw new InvalidOperationException(
-                $"Unable to create AppBuilder from type {entryPointType.Name}." +
+                $"Unable to create AppBuilder from type \"{entryPointType.FullName}\". " +
                 $"Input type either needs to have BuildAvaloniaApp -> AppBuilder method or inherit Application type.");
         }