netdevsim: change fib accounting and limitations to be per-device

netdevsim: change fib accounting and limitations to be per-device

Currently, the accounting is done per-namespace. However, devlink
instance is always in init_net namespace for now, so only the accounting
related to init_net is used. Limitations set using devlink resources
are only considered for init_net. nsim_devlink_net() always
returns init_net always.

Make the accounting per-device. This brings no functional change.
Per-device accounting has the same values as per-net.
For a single netdevsim instance, the behaviour is exactly the same
as before. When multiple netdevsim instances are created, each
can have different limits.

This is in prepare to implement proper devlink netns support. After
that, the devlink instance which would exist in particular netns would
account and limit that netns.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>