Immutable private field might as well be final

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@1004843 13f79535-47bb-0310-9956-ffa450edef68

Author: sebbASF

src/main/java/org/apache/commons/io/input/XmlStreamReader.java

@@ -97,7 +97,7 @@ public class XmlStreamReader extends Reader {
 
     private String encoding;
 
-    private String defaultEncoding;
+    private final String defaultEncoding;
 
     /**
      * Sets the default encoding to use if none is set in HTTP content-type, XML