igb: Fix not adding filter elements to the list

Because the order of the parameters passes to 'hlist_add_behind()' was
inverted, the 'parent' node was added "behind" the 'input', as input
is not in the list, this causes the 'input' node to be lost.

Fixes: 0e71def2 ("igb: add support of RX network flow classification")
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igb/igb_ethtool.c

@@ -2865,7 +2865,7 @@ static int igb_update_ethtool_nfc_entry(struct igb_adapter *adapter,
 
 	/* add filter to the list */
 	if (parent)
-		hlist_add_behind(&parent->nfc_node, &input->nfc_node);
+		hlist_add_behind(&input->nfc_node, &parent->nfc_node);
 	else
 		hlist_add_head(&input->nfc_node, &adapter->nfc_filter_list);