io_uring/poll: always set 'ctx' in io_cancel_data

This isn't strictly necessary for this callsite, as it uses it's
internal lookup for this cancelation purpose. But let's be consistent
with how it's used in general and set ctx as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/poll.c

@@ -972,8 +972,8 @@ int io_poll_add(struct io_kiocb *req, unsigned int issue_flags)
 int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_poll_update *poll_update = io_kiocb_to_cmd(req, struct io_poll_update);
-	struct io_cancel_data cd = { .data = poll_update->old_user_data, };
 	struct io_ring_ctx *ctx = req->ctx;
+	struct io_cancel_data cd = { .ctx = ctx, .data = poll_update->old_user_data, };
 	struct io_hash_bucket *bucket;
 	struct io_kiocb *preq;
 	int ret2, ret = 0;