net/mlx5e: Fix slab-out-of-bounds in mlx5_query_nic_vport_mac_list()

Out_sz that the size of out buffer is calculated using query_nic_vport
_context_in structure when driver query the MAC list. However query_nic
_vport_context_in structure is smaller than query_nic_vport_context_out.
When allowed_list_size is greater than 96, calling ether_addr_copy() will
trigger an slab-out-of-bounds.

[ 1170.055866] BUG: KASAN: slab-out-of-bounds in mlx5_query_nic_vport_mac_list+0x481/0x4d0 [mlx5_core]
[ 1170.055869] Read of size 4 at addr ffff88bdbc57d912 by task kworker/u128:1/461
[ 1170.055870]
[ 1170.055932] Workqueue: mlx5_esw_wq esw_vport_change_handler [mlx5_core]
[ 1170.055936] Call Trace:
[ 1170.055949]  dump_stack+0x8b/0xbb
[ 1170.055958]  print_address_description+0x6a/0x270
[ 1170.055961]  kasan_report+0x179/0x2c0
[ 1170.056061]  mlx5_query_nic_vport_mac_list+0x481/0x4d0 [mlx5_core]
[ 1170.056162]  esw_update_vport_addr_list+0x2c5/0xcd0 [mlx5_core]
[ 1170.056257]  esw_vport_change_handle_locked+0xd08/0x1a20 [mlx5_core]
[ 1170.056377]  esw_vport_change_handler+0x6b/0x90 [mlx5_core]
[ 1170.056381]  process_one_work+0x65f/0x12d0
[ 1170.056383]  worker_thread+0x87/0xb50
[ 1170.056390]  kthread+0x2e9/0x3a0
[ 1170.056394]  ret_from_fork+0x1f/0x40

Fixes: e16aea27

 ("net/mlx5: Introduce access functions to modify/query vport mac lists")
Cc: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Shifeng Li <lishifeng@sangfor.com.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>