Merge branch 'net-convert-exit_batch_rtnl-to-exit_rtnl'

Merge branch 'net-convert-exit_batch_rtnl-to-exit_rtnl'

Kuniyuki Iwashima says:

====================
net: Convert ->exit_batch_rtnl() to ->exit_rtnl().

While converting nexthop to per-netns RTNL, there are two blockers
to using rtnl_net_dereference(), flush_all_nexthops() and
__unregister_nexthop_notifier(), both of which are called from
->exit_batch_rtnl().

Instead of spreading __rtnl_net_lock() over each ->exit_batch_rtnl(),
we should convert all ->exit_batch_rtnl() to per-net ->exit_rtnl() and
run it under __rtnl_net_lock() because all ->exit_batch_rtnl() functions
do not have anything to factor out for batching.

Patch 1 & 2 factorise the undo mechanism against ->init() into a single
function, and Patch 3 adds ->exit_batch_rtnl().

Patch 4 ~ 13 convert all ->exit_batch_rtnl() users.

Patch 14 removes ->exit_batch_rtnl().

Later, we can convert pfcp and ppp to use ->exit_rtnl().

v1: https://lore.kernel.org/all/20250410022004.8668-1-kuniyu@amazon.com/
====================

Link: https://patch.msgid.link/20250411205258.63164-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>