tty: Finish fixing up the init_dev interface to use ERR_PTR

Original suggestion and proposal from Sukadev Bhattiprolu.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 6cc7ccc..54523a3 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -401,8 +401,8 @@
 extern void proc_clear_tty(struct task_struct *p);
 extern struct tty_struct *get_current_tty(void);
 extern void tty_default_fops(struct file_operations *fops);
-extern int tty_init_dev(struct tty_driver *driver, int idx,
-			struct tty_struct **ret_tty, int first_ok);
+extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
+								int first_ok);
 extern void tty_release_dev(struct file *filp);
 
 extern struct mutex tty_mutex;