scripting: fix javadoc error: unknown tag: null

Change-Id: I7d9ec1759a1689943d51636926024278cec0dc3b
Reviewed-on: https://gerrit.libreoffice.org/11234Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>

scripting/java/com/sun/star/script/framework/container/ParcelContainer.java

@@ -118,7 +118,7 @@ public class ParcelContainer implements XNameAccess
      * @param    key the <tt>location</tt> which is to
      *           be matched.
      *
-     * @return    child <tt>ParcelContainer</tt> or <null> if none
+     * @return    child <tt>ParcelContainer</tt> or {@code null} if none
      * found.
      */
 
@@ -148,7 +148,7 @@ public class ParcelContainer implements XNameAccess
      * @param    containerUrl the <tt>containerUrl</tt> which is to
      *           be matched.
      *
-     * @return    child <tt>ParcelContainer</tt> or <null> if none
+     * @return    child <tt>ParcelContainer</tt> or {@code null} if none
      * found.
      */