[dogfooding][cleanup] Use static inner class clean up for
XMLRootElementContentDescriber2

Using this cleanup brings:
- It reviews the feature
 - For optimization: small memory usage reduction as the outer pointer
is removed


Change-Id: Idf3ae5f3040902d1486ec5457ab9663b25ea9fa7
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>
diff --git a/bundles/org.eclipse.core.contenttype/src/org/eclipse/core/runtime/content/XMLRootElementContentDescriber2.java b/bundles/org.eclipse.core.contenttype/src/org/eclipse/core/runtime/content/XMLRootElementContentDescriber2.java
index 4579b09..0faa191 100644
--- a/bundles/org.eclipse.core.contenttype/src/org/eclipse/core/runtime/content/XMLRootElementContentDescriber2.java
+++ b/bundles/org.eclipse.core.contenttype/src/org/eclipse/core/runtime/content/XMLRootElementContentDescriber2.java
@@ -88,7 +88,7 @@
 	/* (Intentionally not included in javadoc)
 	 * Simple value holder for root element name, its namespace and dtd.
 	 */
-	private class QualifiedElement {
+	private static class QualifiedElement {
 		private String namespace;
 		private String element;
 		private String dtd;