i40e: add double of VLAN header when computing the max MTU

stable inclusion
from stable-v5.10.169
commit 23974088fd6a57922abc80ac7d6219572cd48a4f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7V9QX

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=23974088fd6a57922abc80ac7d6219572cd48a4f



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commit ce45ffb8 upstream.

Include the second VLAN HLEN into account when computing the maximum
MTU size as other drivers do.

Fixes: 0c8493d9 ("i40e: add XDP support for pass and drop actions")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: zhaoxiaoqiang11 <zhaoxiaoqiang11@jd.com>