i40evf: don't go further down

If the device is down, there's no place to go but up, so don't try to go
down even more. This prevents a CPU soft lock in napi_disable().

Change-ID: I8b058b9ee974dfa01c212fae2597f4f54b333314
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40evf/i40evf_main.c

@@ -968,6 +968,9 @@ void i40evf_down(struct i40evf_adapter *adapter)
 	struct net_device *netdev = adapter->netdev;
 	struct i40evf_mac_filter *f;
 
+	if (adapter->state == __I40EVF_DOWN)
+		return;
+
 	/* remove all MAC filters */
 	list_for_each_entry(f, &adapter->mac_filter_list, list) {
 		f->remove = true;
@@ -1785,12 +1788,11 @@ static int i40evf_close(struct net_device *netdev)
 	if (adapter->state <= __I40EVF_DOWN)
 		return 0;
 
-	/* signal that we are down to the interrupt handler */
-	adapter->state = __I40EVF_DOWN;
 
 	set_bit(__I40E_DOWN, &adapter->vsi.state);
 
 	i40evf_down(adapter);
+	adapter->state = __I40EVF_DOWN;
 	i40evf_free_traffic_irqs(adapter);
 
 	i40evf_free_all_tx_resources(adapter);