JBR-4871 Closed project leaked via KeyboardFocusManager#newFocusOwner

(cherry picked from commit 50c0ce58d3)

src/java.desktop/share/classes/java/awt/KeyboardFocusManager.java

@@ -2933,6 +2933,8 @@ public abstract class KeyboardFocusManager
                     newFocusOwner = null;
                     return event;
                 }
+
+                newFocusOwner = null;
             }
         }