ixgbe: Do not read the spoofed packets counter when not in IOV mode

The counter is not valid unless the controller is running in IOV mode.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -5560,8 +5560,9 @@ static void ixgbe_spoof_check(struct ixgbe_adapter *adapter)
 {
 	u32 ssvpc;
 
-	/* Do not perform spoof check for 82598 */
-	if (adapter->hw.mac.type == ixgbe_mac_82598EB)
+	/* Do not perform spoof check for 82598 or if not in IOV mode */
+	if (adapter->hw.mac.type == ixgbe_mac_82598EB ||
+	    adapter->num_vfs == 0)
 		return;
 
 	ssvpc = IXGBE_READ_REG(&adapter->hw, IXGBE_SSVPC);