[PATCH net-next v2] selftests: iou-zcrx: Clean up build warnings for error format

[Haiyue Wang <haiyuewa@163.com>]

Clean up two build warnings:

[1]

iou-zcrx.c: In function ‘process_recvzc’:
iou-zcrx.c:263:37: warning: too many arguments for format [-Wformat-extra-args]
  263 |                         error(1, 0, "payload mismatch at ", i);
      |                                     ^~~~~~~~~~~~~~~~~~~~~~

[2] Use "%zd" for ssize_t type as better

iou-zcrx.c: In function ‘run_client’:
iou-zcrx.c:357:47: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘ssize_t’ {aka ‘long int’} [-Wformat=]
  357 |                         error(1, 0, "send(): %d", sent);
      |                                              ~^   ~~~~
      |                                               |   |
      |                                               int ssize_t {aka long int}
      |                                              %ld

Signed-off-by: Haiyue Wang <haiyuewa@163.com>
---
v2:
  - Dont't wrap the build warning message to make scripts/checkpatch.pl happy,
    keep it as for readability.
  - Change the format for ssize_t from "%ld" to "%zd" as Simon suggested.
  - Change the target to net-next tree.
v1: https://lore.kernel.org/netdev/20250502042240.17371-1-haiyuewa@163.com/
---
 tools/testing/selftests/drivers/net/hw/iou-zcrx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index 8aa426014c87..62456df947bc 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -260,7 +260,7 @@ static void process_recvzc(struct io_uring *ring, struct io_uring_cqe *cqe)
 
 	for (i = 0; i < n; i++) {
 		if (*(data + i) != payload[(received + i)])
-			error(1, 0, "payload mismatch at ", i);
+			error(1, 0, "payload mismatch at %d", i);
 	}
 	received += n;
 
@@ -354,7 +354,7 @@ static void run_client(void)
 		chunk = min_t(ssize_t, cfg_payload_len, to_send);
 		res = send(fd, src, chunk, 0);
 		if (res < 0)
-			error(1, 0, "send(): %d", sent);
+			error(1, 0, "send(): %zd", sent);
 		sent += res;
 		to_send -= res;
 	}
-- 
2.49.0