TTY: switch tty_insert_flip_string

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

tty_insert_flip_string this time.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index be6a373..3c285d3 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -120,7 +120,7 @@
 
 	if (c > 0) {
 		/* Stuff the data into the input queue of the other end */
-		c = tty_insert_flip_string(to, buf, c);
+		c = tty_insert_flip_string(to->port, buf, c);
 		/* And shovel */
 		if (c) {
 			tty_flip_buffer_push(to);