i40iw: Fix for LAN handler removal

If i40iw_open() fails for any reason, the LAN handler
is not being removed. Modify i40iw_deinit_device()
to always remove the handler.

Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Henry Orosco <henry.orosco@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>