ixgbe: fix crash on rmmod after probe fail

The driver has logic to free up used data in case any of the checks in
ixgbe_probe() fail, however there is a similar set of cleanups that can
occur on driver unload in ixgbe_remove() which can cause the rmmod command
to crash.

This patch aims to fix the logic by moving pci_set_drvdata() after all error
checks and then adds a check in ixgbe_remove() to skip it altogether if
adapter comes up empty.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -8206,7 +8206,6 @@ static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	SET_NETDEV_DEV(netdev, &pdev->dev);
 
 	adapter = netdev_priv(netdev);
-	pci_set_drvdata(pdev, adapter);
 
 	adapter->netdev = netdev;
 	adapter->pdev = pdev;
@@ -8486,6 +8485,8 @@ skip_sriov:
 	if (err)
 		goto err_register;
 
+	pci_set_drvdata(pdev, adapter);
+
 	/* power down the optics for 82599 SFP+ fiber */
 	if (hw->mac.ops.disable_tx_laser)
 		hw->mac.ops.disable_tx_laser(hw);
@@ -8565,9 +8566,14 @@ err_dma:
 static void ixgbe_remove(struct pci_dev *pdev)
 {
 	struct ixgbe_adapter *adapter = pci_get_drvdata(pdev);
-	struct net_device *netdev = adapter->netdev;
+	struct net_device *netdev;
 	bool disable_dev;
 
+	/* if !adapter then we already cleaned up in probe */
+	if (!adapter)
+		return;
+
+	netdev  = adapter->netdev;
 	ixgbe_dbg_adapter_exit(adapter);
 
 	set_bit(__IXGBE_REMOVING, &adapter->state);