Mark getParent deprecated in CanonicalTreeParser

@deprecated in Javadoc must be accompanied by @Deprecated annotation
on the class member.

Change-Id: Ifdf787f496ff3ffd6ffe8f3321d56320cb08454f

org.eclipse.jgit/src/org/eclipse/jgit/treewalk/CanonicalTreeParser.java

@@ -112,6 +112,7 @@ public class CanonicalTreeParser extends AbstractTreeIterator {
 	 * @return the parent of this tree parser
 	 * @deprecated internal use only
 	 */
+	@Deprecated
 	public CanonicalTreeParser getParent() {
 		return (CanonicalTreeParser) parent;
 	}