asyn-ares: fix build with old c-ares

See https://app.circleci.com/pipelines/github/curl/curl/13081/workflows/7d80b69e-9886-4f4c-b467-0fa321a0f8c2/jobs/130479

Closes #17075

diff --git a/lib/asyn-ares.c b/lib/asyn-ares.c
index 2fb83eeb108c76c3219795396cfdd93a2af3e78a..babae6fb27a77e8da0c7d943a9a6568c06dddf99 100644 (file)
--- a/lib/asyn-ares.c
+++ b/lib/asyn-ares.c
@@ -294,7 +294,7 @@ CURLcode Curl_async_is_resolved(struct Curl_easy *data,
        leave us with res->num_pending == 0, which is perfect for the next
        block. */
     ares_cancel(ares->channel);
-    DEBUGASSERT(res->num_pending == 0);
+    DEBUGASSERT(ares->num_pending == 0);
   }
 #endif