net/mlx5: Fix steering rules cleanup

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5: Fix steering rules cleanup

vport's mc, uc and multicast rules are not deleted in teardown path when

EEH happens. Since the vport's promisc settings(uc, mc and all) in

firmware are reset after EEH, mlx5 driver will try to delete the above

rules in the initialization path. This cause kernel crash because these

software rules are no longer valid.

Fix by nullifying these rules right after delete to avoid accessing any dangling

pointers.

Call Trace:

__list_del_entry_valid+0xcc/0x100 (unreliable)

tree_put_node+0xf4/0x1b0 [mlx5_core]

tree_remove_node+0x30/0x70 [mlx5_core]

mlx5_del_flow_rules+0x14c/0x1f0 [mlx5_core]

esw_apply_vport_rx_mode+0x10c/0x200 [mlx5_core]

esw_update_vport_rx_mode+0xb4/0x180 [mlx5_core]

esw_vport_change_handle_locked+0x1ec/0x230 [mlx5_core]

esw_enable_vport+0x130/0x260 [mlx5_core]

mlx5_eswitch_enable_sriov+0x2a0/0x2f0 [mlx5_core]

mlx5_device_enable_sriov+0x74/0x440 [mlx5_core]

mlx5_load_one+0x114c/0x1550 [mlx5_core]

mlx5_pci_resume+0x68/0xf0 [mlx5_core]

eeh_report_resume+0x1a4/0x230

eeh_pe_dev_traverse+0x98/0x170

eeh_handle_normal_event+0x3e4/0x640

eeh_handle_event+0x4c/0x370

eeh_event_handler+0x14c/0x210

kthread+0x168/0x1b0

ret_from_kernel_thread+0x5c/0x84