io_uring: fix submission-failure handling for uring-cmd

If ->uring_cmd returned an error value different from -EAGAIN or
-EIOCBQUEUED, it gets overridden with IOU_OK. This invites trouble
as caller (io_uring core code) handles IOU_OK differently than other
error codes.
Fix this by returning the actual error code.
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/uring_cmd.c

@@ -112,7 +112,7 @@ int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
 		if (ret < 0)
 			req_set_fail(req);
 		io_req_set_res(req, ret, 0);
-		return IOU_OK;
+		return ret;
 	}
 
 	return IOU_ISSUE_SKIP_COMPLETE;