Fix class cast exception reported in FELIX-411.

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@588633 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/prefs/src/main/java/org/apache/felix/prefs/impl/PreferencesServiceImpl.java b/prefs/src/main/java/org/apache/felix/prefs/impl/PreferencesServiceImpl.java
index 1bf01ce..bed0080 100644
--- a/prefs/src/main/java/org/apache/felix/prefs/impl/PreferencesServiceImpl.java
+++ b/prefs/src/main/java/org/apache/felix/prefs/impl/PreferencesServiceImpl.java
@@ -60,7 +60,7 @@
                 if ( prefs[i].getDescription().getIdentifier() == null ) {
                     this.systemTree = prefs[i];
                 } else {
-                    this.trees.put(prefs[i].getDescription().getIdentifier(), prefs);
+                    this.trees.put(prefs[i].getDescription().getIdentifier(), prefs[i]);
                 }
             }
         } catch (BackingStoreException e) {