Fix for a customer issue with ixl(4):

• Add required MAC/VLAN filter when adding an LAA
• Fix bug where code did not check for I40E_SUCCESS from a successful i40e_validate_mac_address() call in ixl_init_locked(), when setting an LAA.

PR: 201240
Differential Revision: https://reviews.freebsd.org/D3111
Submitted by: Gregory Rose <gregory.v.rose@intel.com>
Reviewed by: gnn, rstone
Approved by: gnn
MFC after: 2 weeks