Use a separate function to calculate the number of stats for
a particular device. This helps reduce the clutter in
i40e_get_sset_count().
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>