i40e: fix format mismatch in drivers/net/ethernet/intel/i40e/i40e_debugfs.c

spotted by cppcheck

Signed-off-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
1 file changed