proc_cleanup_resources () drop instead of immediate removal

kernel/proc/resource.c

@@ -18,9 +18,7 @@ void proc_cleanup_resources (struct proc* proc) {
     struct rb_node_link* next;
     rbtree_next (rnode, next);
     resource = rbtree_entry (rnode, struct proc_resource, proc_resource_tree_link);
-    rbtree_delete (&proc->resource_tree, rnode);
-    resource->ops.cleanup (resource);
-    free (resource);
+    proc_drop_resource (proc, resource);
     rnode = next;
   }