TaskTree: Fix destruction of running task tree

Delete all storages that were created before.

Change-Id: I8cbeb571424086b77fa7b19611c5b3f6cc1f4db1
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/tasktree.h

@@ -45,6 +45,7 @@ private:
     void activateStorage(int id);
 
     struct StorageData {
+        ~StorageData();
         StorageConstructor m_constructor = {};
         StorageDestructor m_destructor = {};
         QHash<int, void *> m_storageHash = {};