net/mlx5: LAG, store demux resources per master lag_func

net/mlx5: LAG, store demux resources per master lag_func

The lag demux resources (flow table, flow group, and rules xarray)
are stored on the shared ldev. With Socket Direct, multiple SD groups
each create their own demux FT/FG during their master's IB device
initialization. Since they all write to the same ldev fields, the
second group's init overwrites the first group's pointers, leaking
the first group's FT/FG.

During teardown, the cleanup uses the overwritten pointers, destroying
the wrong group's resources and leaving leaked flow tables in the LAG
namespace. These leaked tables can interfere with subsequently created
demux tables.

Move the demux resources from the shared ldev to per-master lag_func
instances. Each master device now owns its own independent demux
state. The rule_add and rule_del helpers look up the appropriate
master's lag_func via the existing filter/group infrastructure.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260612113904.537595-10-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>