net/mlx5e: Use correct encap attribute during invalidation

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

net/mlx5e: Use correct encap attribute during invalidation

With introduction of post action infrastructure most of the users of encap
attribute had been modified in order to obtain the correct attribute by
calling mlx5e_tc_get_encap_attr() helper instead of assuming encap action
is always on default attribute. However, the cited commit didn't modify
mlx5e_invalidate_encap() which prevents it from destroying correct modify
header action which leads to a warning [0]. Fix the issue by using correct
attribute.

[0]:

Feb 21 09:47:35 c-237-177-40-045 kernel: WARNING: CPU: 17 PID: 654 at drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:684 mlx5e_tc_attach_mod_hdr+0x1cc/0x230 [mlx5_core]
Feb 21 09:47:35 c-237-177-40-045 kernel: RIP: 0010:mlx5e_tc_attach_mod_hdr+0x1cc/0x230 [mlx5_core]
Feb 21 09:47:35 c-237-177-40-045 kernel: Call Trace:
Feb 21 09:47:35 c-237-177-40-045 kernel: <TASK>
Feb 21 09:47:35 c-237-177-40-045 kernel: mlx5e_tc_fib_event_work+0x8e3/0x1f60 [mlx5_core]
Feb 21 09:47:35 c-237-177-40-045 kernel: ? mlx5e_take_all_encap_flows+0xe0/0xe0 [mlx5_core]
Feb 21 09:47:35 c-237-177-40-045 kernel: ? lock_downgrade+0x6d0/0x6d0
Feb 21 09:47:35 c-237-177-40-045 kernel: ? lockdep_hardirqs_on_prepare+0x273/0x3f0
Feb 21 09:47:35 c-237-177-40-045 kernel: ? lockdep_hardirqs_on_prepare+0x273/0x3f0
Feb 21 09:47:35 c-237-177-40-045 kernel: process_one_work+0x7c2/0x1310
Feb 21 09:47:35 c-237-177-40-045 kernel: ? lockdep_hardirqs_on_prepare+0x3f0/0x3f0
Feb 21 09:47:35 c-237-177-40-045 kernel: ? pwq_dec_nr_in_flight+0x230/0x230
Feb 21 09:47:35 c-237-177-40-045 kernel: ? rwlock_bug.part.0+0x90/0x90
Feb 21 09:47:35 c-237-177-40-045 kernel: worker_thread+0x59d/0xec0
Feb 21 09:47:35 c-237-177-40-045 kernel: ? __kthread_parkme+0xd9/0x1d0