copperplate/registry: use plain malloc/free in fusefs handlers
fusefs handlers are processed on behalf of the non-rt fusefs server thread, which never holds rt locks by design while issuing memory management calls (e.g. collect_wait_list()). So there is no need to pull memory from the private real-time allocator which storage may be limited, plain malloc is fine. At this chance, add a few missing __STD() notations to existing free() calls paired with __STD(malloc()).