TTY: devpts, do not set driver_data

The goal is to stop setting and using tty->driver_data in devpts code.
It should be used solely by the driver's code, pty in this case.

Now driver_data are managed only in the pty driver. devpts_pty_new is
switched to accept what we used to dig out of tty_struct, i.e. device
node number and index.

This also removes a note about driver_data being set outside of the
driver.

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/devpts_fs.h b/include/linux/devpts_fs.h
index 4ca846f..251a209 100644
--- a/include/linux/devpts_fs.h
+++ b/include/linux/devpts_fs.h
@@ -20,11 +20,12 @@
 int devpts_new_index(struct inode *ptmx_inode);
 void devpts_kill_index(struct inode *ptmx_inode, int idx);
 /* mknod in devpts */
-struct inode *devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty);
+struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
+		void *priv);
 /* get private structure */
 void *devpts_get_priv(struct inode *pts_inode);
 /* unlink */
-void devpts_pty_kill(struct tty_struct *tty);
+void devpts_pty_kill(struct inode *inode);
 
 #else
 
@@ -32,7 +33,7 @@
 static inline int devpts_new_index(struct inode *ptmx_inode) { return -EINVAL; }
 static inline void devpts_kill_index(struct inode *ptmx_inode, int idx) { }
 static inline struct inode *devpts_pty_new(struct inode *ptmx_inode,
-		struct tty_struct *tty)
+		dev_t device, int index, void *priv)
 {
 	return ERR_PTR(-EINVAL);
 }
@@ -40,7 +41,7 @@
 {
 	return NULL;
 }
-static inline void devpts_pty_kill(struct tty_struct *tty) { }
+static inline void devpts_pty_kill(struct inode *inode) { }
 
 #endif