r6040: use module_pci_driver macro

as the manual of module_pci_driver says that
it can be used when the init and exit functions of
the module does nothing but the pci_register_driver
and pci_unregister_driver.

use it for rdc's r6040 driver, as the init and exit
paths does as above, and also this reduces a little
amount of code.
Signed-off-by: NDevendra Naga <devendra.aaru@gmail.com>
Acked-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/rdc/r6040.c

@@ -1277,17 +1277,4 @@ static struct pci_driver r6040_driver = {
 	.remove		= __devexit_p(r6040_remove_one),
 };
 
-
-static int __init r6040_init(void)
-{
-	return pci_register_driver(&r6040_driver);
-}
-
-
-static void __exit r6040_cleanup(void)
-{
-	pci_unregister_driver(&r6040_driver);
-}
-
-module_init(r6040_init);
-module_exit(r6040_cleanup);
+module_pci_driver(r6040_driver);