Merge branch 'udp_tunnel-speed-up-udp-tunnel-device-destruction-part-ii'

Kuniyuki Iwashima says:

====================
udp_tunnel: Speed up UDP tunnel device destruction (Part II)

Most of the UDP tunnel devices called synchronize_rcu() twice
during destruction, for example, vxlan had

  1) synchronize_rcu() in udp_tunnel_sock_release()

  2) synchronize_net() in vxlan_sock_release()

The former was already removed by:
https://lore.kernel.org/netdev/20260502031401.3557229-1-kuniyu@google.com/

This series removes the latter.

Patch 1 & 2 & 4 remove synchronize_net() placed before
udp_tunnel_sock_release().

Patch 3 removes yet another unnecessary synchronize_net() in
geneve_unquiesce().

Patch 5 is a follow-up patch for a sparse report by kernel test robot.
====================

Link: https://patch.msgid.link/20260518050726.318824-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>