igc: Refactor igc_del_mac_filter()

int igc_del_mac_filter(struct igc_adapter *adapter, const u8 *addr,

		       const u8 flags)

{

	struct igc_hw *hw = &adapter->hw;

	int rar_entries = hw->mac.rar_entry_count;

	int i;

	struct igc_mac_addr *entry;

	int index;

	if (!is_valid_ether_addr(addr))

		return -EINVAL;

	for (i = 0; i < rar_entries; i++) {

		if (!(adapter->mac_table[i].state & IGC_MAC_STATE_IN_USE))

			continue;

		if (flags && (adapter->mac_table[i].state & flags) != flags)

			continue;

		if (!ether_addr_equal(adapter->mac_table[i].addr, addr))

			continue;

	index = igc_find_mac_filter(adapter, addr, flags);

	if (index < 0)

		return -ENOENT;

	entry = &adapter->mac_table[index];

		/* When a filter for the default address is "deleted",

		 * we return it to its initial configuration

	if (entry->state & IGC_MAC_STATE_DEFAULT) {

		/* If this is the default filter, we don't actually delete it.

		 * We just reset to its default value i.e. disable queue

		 * assignment.

		 */

		if (adapter->mac_table[i].state & IGC_MAC_STATE_DEFAULT) {

			adapter->mac_table[i].state =

				IGC_MAC_STATE_DEFAULT | IGC_MAC_STATE_IN_USE;

			adapter->mac_table[i].queue = -1;

			igc_set_mac_filter_hw(adapter, 0, addr, -1);

		entry->queue = -1;

		igc_set_mac_filter_hw(adapter, 0, addr, entry->queue);

	} else {

			adapter->mac_table[i].state = 0;

			adapter->mac_table[i].queue = -1;

			memset(adapter->mac_table[i].addr, 0, ETH_ALEN);

			igc_clear_mac_filter_hw(adapter, i);

		entry->state = 0;

		entry->queue = -1;

		memset(entry->addr, 0, ETH_ALEN);

		igc_clear_mac_filter_hw(adapter, index);

	}

	return 0;

}

	return -ENOENT;

}

static int igc_uc_sync(struct net_device *netdev, const unsigned char *addr)

{

	struct igc_adapter *adapter = netdev_priv(netdev);