drivers/misc/ti-st: Prefer tty_driver_flush_buffer

The tty core provides an interface for flushing the driver's
write buffer: tty_driver_flush_buffer(); prefer the provided
interface over open-coded. Open-coding can lead to errors
such as the duplicated call in the st_kim driver.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/ti-st/st_core.c

@@ -812,7 +812,7 @@ static void st_tty_flush_buffer(struct tty_struct *tty)
 	kfree_skb(st_gdata->tx_skb);
 	st_gdata->tx_skb = NULL;
 
-	tty->ops->flush_buffer(tty);
+	tty_driver_flush_buffer(tty);
 	return;
 }
 

drivers/misc/ti-st/st_kim.c

@@ -531,7 +531,6 @@ long st_kim_stop(void *kim_data)
 		/* Flush any pending characters in the driver and discipline. */
 		tty_ldisc_flush(tty);
 		tty_driver_flush_buffer(tty);
-		tty->ops->flush_buffer(tty);
 	}
 
 	/* send uninstall notification to UIM */