TTY: switch tty_insert_flip_char

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_char is the next one to proceed. This one is used all
over the code, so the patch is huge.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 4011386..450c450 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -2079,7 +2079,7 @@
 		}
 		while (gdl--) {
 			ch = inb(port->ioaddr + UART_RX);
-			tty_insert_flip_char(tty, ch, 0);
+			tty_insert_flip_char(&port->port, ch, 0);
 			cnt++;
 		}
 		goto end_intr;
@@ -2118,7 +2118,7 @@
 				} else
 					flag = TTY_BREAK;
 			}
-			tty_insert_flip_char(tty, ch, flag);
+			tty_insert_flip_char(&port->port, ch, flag);
 			cnt++;
 			if (cnt >= recv_room) {
 				if (!port->ldisc_stop_rx)