[SERIAL] ip22zilog: Fix oops on runlevel change with serial console

Incorrect uart_write_wakeup() calls cause reference to a NULL tty
pointer.  This has been fixed in the sunsab and sunzilog serial drivers
in October 2005.  Update the ip22zilog, which is based on sunzilog,
accordingly.

Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk
diff --git a/drivers/serial/ip22zilog.c b/drivers/serial/ip22zilog.c
index 419dd3c..193722d 100644
--- a/drivers/serial/ip22zilog.c
+++ b/drivers/serial/ip22zilog.c
@@ -420,10 +420,8 @@
 	if (up->port.info == NULL)
 		goto ack_tx_int;
 	xmit = &up->port.info->xmit;
-	if (uart_circ_empty(xmit)) {
-		uart_write_wakeup(&up->port);
+	if (uart_circ_empty(xmit))
 		goto ack_tx_int;
-	}
 	if (uart_tx_stopped(&up->port))
 		goto ack_tx_int;