tty: Remove external interface for tty_set_termios()

tty_set_termios() is an internal helper intended for file scope use.

UART drivers which are capable of driving the RTS pin must
properly handle the tiocmset() method, regardless of termios settings.
A failure to do so is a UART driver bug and should be fixed there.
Do not use this interface to workaround UART driver bugs.

Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: <linux-bluetooth@vger.kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_ioctl.c

@@ -530,7 +530,7 @@ EXPORT_SYMBOL(tty_termios_hw_change);
  *	Locking: termios_rwsem
  */
 
-int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
+static int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
 {
 	struct ktermios old_termios;
 	struct tty_ldisc *ld;
@@ -563,7 +563,6 @@ int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
 	up_write(&tty->termios_rwsem);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(tty_set_termios);
 
 /**
  *	set_termios		-	set termios values for a tty