i40e: remove code to handle dev_addr specially

The netdev->dev_addr MAC filter already exists in the
MAC/VLAN hash table, as it is added when we configure
the netdev in i40e_configure_netdev. Because we already
know that this address will be updated in the
hash_for_each loops, we do not need to handle it
specially. This removes duplicate code and simplifies
the i40e_vsi_add_vlan and i40e_vsi_kill_vlan functions.
Because we know these filters must be part of the
MAC/VLAN hash table, this should not have any functional
impact on what filters are included and is merely a code
simplification.

Change-ID: I5e648302dbdd7cc29efc6d203b7019c11f0b5705
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>