i40e: fix confusing message

This patch fixes the confusing kernel message of enabled RSS size,
by reporting it together with the hardware maximum RSS size.

Change-ID: I64864dbfbc13beccc180a7871680def1f3d5a339
Signed-off-by: Helin Zhang <helin.zhang@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>