Merge branch 'neighbour-convert-rtm_getneightbl-and-rtm_setneightbl-to-rcu'

Merge branch 'neighbour-convert-rtm_getneightbl-and-rtm_setneightbl-to-rcu'

Kuniyuki Iwashima says:

====================
neighbour: Convert RTM_GETNEIGHTBL and RTM_SETNEIGHTBL to RCU.

Patch 1 & 2 are prep for RCU conversion for RTM_GETNEIGHTBL.

Patch 3 & 4 converts RTM_GETNEIGHTBL and RTM_SETNEIGHTBL to RCU.

Patch 5 converts the neighbour table rwlock to the plain spinlock.
====================

Link: https://patch.msgid.link/20251022054004.2514876-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>