rxrpc: use bvec_set_page to initialize a bvec

Use the bvec_set_page helper to initialize a bvec.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20230203150634.3199647-21-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

net/rxrpc/rxperf.c

@@ -493,7 +493,7 @@ static int rxperf_deliver_request(struct rxperf_call *call)
 static int rxperf_process_call(struct rxperf_call *call)
 {
 	struct msghdr msg = {};
-	struct bio_vec bv[1];
+	struct bio_vec bv;
 	struct kvec iov[1];
 	ssize_t n;
 	size_t reply_len = call->reply_len, len;
@@ -503,10 +503,8 @@ static int rxperf_process_call(struct rxperf_call *call)
 
 	while (reply_len > 0) {
 		len = min_t(size_t, reply_len, PAGE_SIZE);
-		bv[0].bv_page	= ZERO_PAGE(0);
-		bv[0].bv_offset	= 0;
-		bv[0].bv_len	= len;
-		iov_iter_bvec(&msg.msg_iter, WRITE, bv, 1, len);
+		bvec_set_page(&bv, ZERO_PAGE(0), len, 0);
+		iov_iter_bvec(&msg.msg_iter, WRITE, &bv, 1, len);
 		msg.msg_flags = MSG_MORE;
 		n = rxrpc_kernel_send_data(rxperf_socket, call->rxcall, &msg,
 					   len, rxperf_notify_end_reply_tx);