BUG/MINOR: quic: fix ack range node pool_free call passing wrong pointer type

In quic_insert_new_range(), the variable 'first' is a struct eb64_node*,
but pool_free expects a struct quic_arng_node*. While the addresses are identical
(since 'first' is the first member of quic_arng_node), this is technically
incorrect and should use eb64_entry() for proper type safety.

Must be backported to all versions.

src/quic_ack.c

@@ -86,7 +86,7 @@ struct quic_arng_node *quic_insert_new_range(struct quic_conn *qc,
 		first = eb64_first(&arngs->root);
 		BUG_ON(first == NULL);
 		eb64_delete(first);
-		pool_free(pool_head_quic_arng, first);
+		pool_free(pool_head_quic_arng, eb64_entry(first, struct quic_arng_node, first));
 		arngs->sz--;
 	}