tty: Move the vt_tty field from the vc_data into the standard tty_port

This takes all the tty references through the expected interface points so
we can refcount them.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index cb19dbc..72dcfb2 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -1369,7 +1369,7 @@
 	acquire_console_sem();
 	vc = vc_con->d;
 	if (vc) {
-		tty = vc->vc_tty;
+		tty = vc->port.tty;
 		/*
 		 * SAK should also work in all raw modes and reset
 		 * them properly.