e1000e: do not suggest the driver supports Wake-on-ARP

The driver doesn't support Wake-on-ARP, so don't advertise through ethtool
that it does.

Cleanup some coding style issues in the same functions.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>