gfar: Fix modpost warning

Fix the following modpost warning:

WARNING: vmlinux.o(.init.text+0x1aa6c): Section mismatch: reference to .exit.text:gfar_mdio_exit (between 'gfar_init' and 'gfar_mdio_init')

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/gianfar_mii.c

@@ -245,7 +245,7 @@ int __init gfar_mdio_init(void)
 	return driver_register(&gianfar_mdio_driver);
 }
 
-void __exit gfar_mdio_exit(void)
+void gfar_mdio_exit(void)
 {
 	driver_unregister(&gianfar_mdio_driver);
 }