TTY: add tty_port_tty_wakeup helper

It allows for cleaning up on a considerable amount of places. They did
port_get, wakeup, kref_put. Now the only thing needed is to call
tty_port_tty_wakeup which does exactly that.

One exception is ifx6x60 where tty_wakeup was open-coded. We now call
tty_wakeup properly there.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/s390/char/sclp_tty.c b/drivers/s390/char/sclp_tty.c
index 14b4cb8..7ed7a59 100644
--- a/drivers/s390/char/sclp_tty.c
+++ b/drivers/s390/char/sclp_tty.c
@@ -107,7 +107,6 @@
 static void
 sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
 {
-	struct tty_struct *tty;
 	unsigned long flags;
 	void *page;
 
@@ -125,12 +124,8 @@
 					    struct sclp_buffer, list);
 		spin_unlock_irqrestore(&sclp_tty_lock, flags);
 	} while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
-	/* check if the tty needs a wake up call */
-	tty = tty_port_tty_get(&sclp_port);
-	if (tty != NULL) {
-		tty_wakeup(tty);
-		tty_kref_put(tty);
-	}
+
+	tty_port_tty_wakeup(&sclp_port);
 }
 
 static inline void