Private immutable field might as well be final

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/jci/trunk@1516031 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/fam/src/main/java/org/apache/commons/jci/monitor/FilesystemAlterationObserverImpl.java b/fam/src/main/java/org/apache/commons/jci/monitor/FilesystemAlterationObserverImpl.java
index d20d02c..e7f5c16 100644
--- a/fam/src/main/java/org/apache/commons/jci/monitor/FilesystemAlterationObserverImpl.java
+++ b/fam/src/main/java/org/apache/commons/jci/monitor/FilesystemAlterationObserverImpl.java
@@ -98,7 +98,7 @@
         private final MonitorFile file;
         private long lastModified = -1;
         private int lastType = TYPE_UNKNOWN;
-        private Map<String, Entry> children = new HashMap<String, Entry>();
+        private final Map<String, Entry> children = new HashMap<String, Entry>();
 
         public Entry(final MonitorFile pFile) {
             file = pFile;