The function description for igc_alloc_rx_buffers has not reflected
the function meaning. Add meaningful description.
Signed-off-by: NSasha Neftin <sasha.neftin@intel.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>