TTY: move cdev_add to tty_register_device

We need the /dev/ node not to be available before we call
tty_register_device. Otherwise we might race with open and
tty_struct->port might not be available at that time.

This is not an issue now, but would be a problem after "TTY: use
tty_port_register_device" is applied.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 44e05b7..dd976cf 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -289,7 +289,7 @@
 struct tty_driver {
 	int	magic;		/* magic number for this structure */
 	struct kref kref;	/* Reference management */
-	struct cdev cdev;
+	struct cdev *cdevs;
 	struct module	*owner;
 	const char	*driver_name;
 	const char	*name;