udp_client/http_clnt: print success message

Ref #2139

repos/dde_linux/src/test/lxip/udp_client/main.cc

@@ -73,5 +73,7 @@ int main(void)
 		log("Received \"", String<64>(buf), " ...\"");
 	}
 	_timer.msleep(2000);
+
+	log("Test done");
 	return 0;
 }

repos/libports/src/test/lwip/http_clnt/main.cc

@@ -165,5 +165,6 @@ int main()
 		lwip_close(s);
 	}
 
+	log("Test done");
 	return 0;
 }