io_uring: fail links if msg-ring doesn't succeeed

We must always call req_set_fail() if the request is failed, otherwise
we won't sever links for dependent chains correctly.

Fixes: 4f57f06c ("io_uring: add support for IORING_OP_MSG_RING command")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -4500,6 +4500,8 @@ static int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags)
 		ret = 0;
 	}
 
+	if (ret < 0)
+		req_set_fail(req);
 	__io_req_complete(req, issue_flags, ret, 0);
 	return 0;
 }