io_uring/zcrx: clear RQ headers on init

It might be unexpected to users if the RQ head/tail after a ring
creation are not zeroed, fix that.

Cc: [email protected]
Fixes: 6f37787 ("io_uring/zcrx: add interface queue and refill queue")
Signed-off-by: Pavel Begunkov <[email protected]>
Link: https://patch.msgid.link/331f94663c3e8f021ffa3cb770ca2844a07d4855.1776760911.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <[email protected]>

Author: isilence

io_uring/zcrx.c

@@ -396,6 +396,7 @@ static int io_allocate_rbuf_ring(struct io_ring_ctx *ctx,
 	ifq->rq.ring = (struct io_uring *)ptr;
 	ifq->rq.rqes = (struct io_uring_zcrx_rqe *)(ptr + off);
 
+	memset(ifq->rq.ring, 0, sizeof(*ifq->rq.ring));
 	return 0;
 }