i40e: clear VEB stats when pf stats are cleared

The VEB really is part of the whole PF and should be cleared
at the same time.

Change-ID: Ia1d4d1df5cf421f2578a22486650dd256cc4617a
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>