remove of condition unecessary (#425)

Author: lucasnobredev

snippets/csharp/programming-guide/discards/discard-pattern2.cs

@@ -21,7 +21,7 @@ private static void ProvidesFormatInfo(object obj)
          Console.Write("A null object reference: ");
          Console.WriteLine("Its use could result in a NullReferenceException");
       }
-      else if (obj is var _)
+      else
          Console.WriteLine($"Some object type without format information");
    }
 }