ibmvnic: Validate napi exist before disabling them

Validate that the napi structs exist before trying to disable them
at driver close.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 115f2169..5a916a2 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -729,8 +729,10 @@ static int ibmvnic_close(struct net_device *netdev)
 	adapter->closing = true;
 	disable_sub_crqs(adapter);
 
-	for (i = 0; i < adapter->req_rx_queues; i++)
-		napi_disable(&adapter->napi[i]);
+	if (adapter->napi) {
+		for (i = 0; i < adapter->req_rx_queues; i++)
+			napi_disable(&adapter->napi[i]);
+	}
 
 	if (!adapter->failover)
 		netif_tx_stop_all_queues(netdev);