Fix typo in bufferingModeStrings array

Author: gewarren

snippets/csharp/System.Drawing/BufferedGraphics/Overview/bufferingtest.cs

@@ -13,7 +13,7 @@ public class BufferingExample : Form
 
         private byte bufferingMode;
         private string[] bufferingModeStrings =
-            [ "Draw to Form without OptimizedDoubleBufferring control style",
+            [ "Draw to Form without OptimizedDoubleBuffering control style",
           "Draw to Form using OptimizedDoubleBuffering control style",
           "Draw to HDC for form" ];