remove is_tty()

This patch removes the no longer used is_tty().
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/tty_io.c

@@ -1119,19 +1119,6 @@ int tty_hung_up_p(struct file *filp)
 
 EXPORT_SYMBOL(tty_hung_up_p);
 
-/**
- *	is_tty	-	checker whether file is a TTY
- *	@filp:		file handle that may be a tty
- *
- *	Check if the file handle is a tty handle.
- */
-
-int is_tty(struct file *filp)
-{
-	return filp->f_op->read == tty_read
-		|| filp->f_op->read == hung_up_tty_read;
-}
-
 static void session_clear_tty(struct pid *session)
 {
 	struct task_struct *p;