io_uring/zcrx: don't adjust free cache space

The cache should be empty when io_pp_zc_alloc_netmems() is called,
that's promised by page pool and further checked, so there is no need to
recalculate the available space in io_zcrx_ring_refill().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

io_uring/zcrx.c

@@ -759,7 +759,7 @@ static void io_zcrx_ring_refill(struct page_pool *pp,
 	guard(spinlock_bh)(&ifq->rq_lock);
 
 	entries = io_zcrx_rqring_entries(ifq);
-	entries = min_t(unsigned, entries, PP_ALLOC_CACHE_REFILL - pp->alloc.count);
+	entries = min_t(unsigned, entries, PP_ALLOC_CACHE_REFILL);
 	if (unlikely(!entries))
 		return;