BUG/MAJOR: quic: Useless resource intensive loop qc_ackrng_pkts()

This usless loop should have been removed a long time ago. As it is CPU resource
intensive, it could trigger the watchdog.

Must be backported to 2.6.
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 2c66058..4a77db1 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -1602,15 +1602,7 @@
 	struct eb64_node *node;
 	struct quic_tx_packet *pkt;
 
-	if (largest_node)
-		node = largest_node;
-	else {
-		node = eb64_lookup(pkts, largest);
-		while (!node && largest > smallest) {
-			node = eb64_lookup(pkts, --largest);
-		}
-	}
-
+	node = largest_node ? largest_node : eb64_lookup_le(pkts, largest);
 	while (node && node->key >= smallest) {
 		struct quic_frame *frm, *frmbak;