ixgbe: fix registration order of driver and DCA nofitication

commit f01fc1a8 upstream.

ixgbe_notify_dca cannot be called before driver registration
because it expects driver's klist_devices to be allocated and
initialized. While on it make sure debugfs files are removed
when registration fails.
Signed-off-by: Jakub Kicinski <jakub.kicinski@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: no debugfs support]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

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

@@ -8003,12 +8003,15 @@ static int __init ixgbe_init_module(void)
 	pr_info("%s - version %s\n", ixgbe_driver_string, ixgbe_driver_version);
 	pr_info("%s\n", ixgbe_copyright);
 
+	ret = pci_register_driver(&ixgbe_driver);
+	if (ret)
+		return ret;
+
 #ifdef CONFIG_IXGBE_DCA
 	dca_register_notify(&dca_notifier);
 #endif
 
-	ret = pci_register_driver(&ixgbe_driver);
-	return ret;
+	return 0;
 }
 
 module_init(ixgbe_init_module);