TTY: move low_latency to tty_port

One point is to have less places where we actually need tty pointer.
The other is that low_latency is bound to buffer processing and
buffers are now in tty_port. So it makes sense to move low_latency to
tty_port too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c
index f5794f3..419f58f 100644
--- a/drivers/tty/synclinkmp.c
+++ b/drivers/tty/synclinkmp.c
@@ -761,7 +761,7 @@
 		goto cleanup;
 	}
 
-	info->port.tty->low_latency = (info->port.flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+	info->port.low_latency = (info->port.flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 
 	spin_lock_irqsave(&info->netlock, flags);
 	if (info->netcount) {