MINOR: quic: Stop looking for packet loss asap

As the TX packets are ordered by their packet number and always sent
in the same order. their TX timestamps are inspected from the older to
the newer values when we look for the packet loss. So we can stop
this search as soon as we found the first packet which has not been lost.

Must be backported to 2.6

src/quic_loss.c

@@ -184,6 +184,7 @@ void qc_packet_loss_lookup(struct quic_pktns *pktns, struct quic_conn *qc,
 				pktns->tx.loss_time = tick_first(pktns->tx.loss_time, loss_time_limit);
 			else
 				pktns->tx.loss_time = loss_time_limit;
+			break;
 		}
 	}