tty: Remove tty_pair_get_tty()/tty_pair_get_pty() api

tty_pair_get_pty() has no in-tree users and tty_pair_get_tty()
has only one file-local user. Remove the external declarations,
the export declarations, and declare tty_pair_get_tty() static.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_io.c

@@ -2703,23 +2703,17 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
 	return 0;
 }
 
-struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
+/*
+ * if pty, return the slave side (real_tty)
+ * otherwise, return self
+ */
+static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
 {
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 	    tty->driver->subtype == PTY_TYPE_MASTER)
 		tty = tty->link;
 	return tty;
 }
-EXPORT_SYMBOL(tty_pair_get_tty);
-
-struct tty_struct *tty_pair_get_pty(struct tty_struct *tty)
-{
-	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
-	    tty->driver->subtype == PTY_TYPE_MASTER)
-	    return tty;
-	return tty->link;
-}
-EXPORT_SYMBOL(tty_pair_get_pty);
 
 /*
  * Split this up, as gcc can choke on it otherwise..

include/linux/tty.h

@@ -498,9 +498,6 @@ extern int tty_init_termios(struct tty_struct *tty);
 extern int tty_standard_install(struct tty_driver *driver,
 		struct tty_struct *tty);
 
-extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
-extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);
-
 extern struct mutex tty_mutex;
 extern spinlock_t tty_files_lock;