ice: fix kernel BUG if register_netdev fails

If register_netdev() fails, the driver will attempt to cleanup the
q_vectors and inadvertently trigger a kernel BUG due to a NULL pointer
dereference.

This occurs because cleaning up q_vectors attempts to call
netif_napi_del on napi_structs which were never initialized.

Resolve this by releasing the netdev in ice_cfg_netdev and setting
vsi->netdev to NULL. This ensures that after ice_cfg_netdev fails the
state is rewound to match as if ice_cfg_netdev was never called.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ice/ice_main.c

@@ -2428,7 +2428,7 @@ static int ice_cfg_netdev(struct ice_vsi *vsi)
 
 	err = register_netdev(vsi->netdev);
 	if (err)
-		goto err_destroy_devlink_port;
+		goto err_free_netdev;
 
 	devlink_port_type_eth_set(&pf->devlink_port, vsi->netdev);
 
@@ -2439,9 +2439,11 @@ static int ice_cfg_netdev(struct ice_vsi *vsi)
 
 	return 0;
 
+err_free_netdev:
+	free_netdev(vsi->netdev);
+	vsi->netdev = NULL;
 err_destroy_devlink_port:
 	ice_devlink_destroy_port(pf);
-
 	return err;
 }