tcp-handler: log TLS receive errors

src/knot/server/tcp-handler.c

@@ -175,7 +175,9 @@ static int tcp_handle(tcp_context_t *tcp, knotd_qdata_params_t *params,
 			recv = knot_tls_recv_dns(params->tls_conn, rx->iov_base, rx->iov_len);
 			break;
 		default: // E.g. handshake timeout.
-			return ret;
+			assert(ret < 0);
+			recv = ret;
+			break;
 		}
 	} else {
 		recv = net_dns_tcp_recv(params->socket, rx->iov_base, rx->iov_len, tcp->io_timeout);