netfilter: nf_tables: fix kdoc warnings after gc rework

netfilter: nf_tables: fix kdoc warnings after gc rework

Jakub Kicinski says:
  We've got some new kdoc warnings here:
  net/netfilter/nft_set_pipapo.c:1557: warning: Function parameter or member '_set' not described in 'pipapo_gc'
  net/netfilter/nft_set_pipapo.c:1557: warning: Excess function parameter 'set' description in 'pipapo_gc'
  include/net/netfilter/nf_tables.h:577: warning: Function parameter or member 'dead' not described in 'nft_set'

Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Fixes: f6c383b8c31a ("netfilter: nf_tables: adapt set backend to use GC transaction API")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20230810104638.746e46f1@kernel.org/
Signed-off-by: Florian Westphal <fw@strlen.de>
(cherry picked from commit 08713cb006b6f07434f276c5ee214fb20c7fd965)
CVE-2023-4244
[cengizcan: fixes the fix commit]
Signed-off-by: Cengiz Can <cengiz.can@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>