check error in TestDNSCycleRecursorCheckAllFail before asserting response to stop panic in CI. (#20231)

agent/dns_test.go

@@ -320,7 +320,8 @@ func TestDNSCycleRecursorCheckAllFail(t *testing.T) {
 			m.SetQuestion("google.com.", dns.TypeA)
 			// Agent request
 			client := new(dns.Client)
-			in, _, _ := client.Exchange(m, agent.DNSAddr())
+			in, _, err := client.Exchange(m, agent.DNSAddr())
+			require.NoError(t, err)
 			// Verify if we hit SERVFAIL from Consul
 			require.Equal(t, dns.RcodeServerFailure, in.Rcode)
 		})