NestedIOException can use IOException constructor with cause argument on JDK 6+

(cherry picked from commit c18b6bf)

spring-core/src/main/java/org/springframework/core/NestedIOException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -60,8 +60,7 @@ public class NestedIOException extends IOException {
 	 * @param cause the nested exception
 	 */
 	public NestedIOException(String msg, Throwable cause) {
-		super(msg);
-		initCause(cause);
+		super(msg, cause);
 	}