[PATCH net-next v3 4/4] net/sched/sch_cake: drop dead nla_nest_end() error check

cake_dump_class_stats() closes the TCA_STATS_APP nest with

	if (nla_nest_end(d->skb, stats) < 0)
		return -1;

nla_nest_end() never returns a negative value: it has a single
`return skb->len;` and no error path (that is why the overflow-aware
nla_nest_end_safe() helper was later added). The '< 0' test can never
be true, so the 'return -1' is unreachable dead code.

Drop the check and close the nest with the bare statement, matching the
sibling cake nests in the same file.

This issue was discovered while fixing a bug on the gate action, see:
https://lore.kernel.org/netdev/QDISC-H19Z.v1.20261001053234@mojatatu.com/ (local)

Conditions to recreate the bug:
- not runtime observable: the issue is found by inspection.

Link: https://lore.kernel.org/netdev/87v77csd5q.fsf@toke.dk/ (local)
Reviewed-by: Victor Nogueira <redacted>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
---
v2 -> v3:
 - No changes to this patch. Re-sent as part of the series v3; keeps its Reviewed-by and Acked-by tags.

v1 -> v2:
 - No changes to this patch. Re-sent as part of the
   series v2; it keeps Toke's v1 Acked-by, carried forward.

 net/sched/sch_cake.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 4caf9718c9bd..124f552023f8 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c

@@ -3211,8 +3211,7 @@ static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 						       READ_ONCE(flow->cvars.drop_next))));
 		}
 
-		if (nla_nest_end(d->skb, stats) < 0)
-			return -1;
+		nla_nest_end(d->skb, stats);
 	}
 
 	return 0;

-- 
2.43.0