net: move netdev_max_backlog to net_hotdata

netdev_max_backlog is used in rx fat path.

Move it to net_hodata for better cache locality.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240306160031.874438-6-edumazet@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>