ice: Restore fix disabling RX VLAN filtering

Fix setting dis_rx_filtering depending on whether port vlan is being
turned on or off. This was originally fixed in commit c793f8ea ("ice:
Fix disabling Rx VLAN filtering with port VLAN enabled"), but while
refactoring ice_vf_vsi_init_vlan_ops(), the fix has been lost. Restore the
fix along with the original comment from that change.

Also delete duplicate lines in ice_port_vlan_on().

Fixes: 2946204b ("ice: implement bridge port vlan")
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>