[SERIAL] initialize spinlock for port failed to setup console

It seems serial_core intend to initialize port->lock just once for each
ports.  This is done in uart_set_options() for console, and in
uart_add_one_port() for other ports.  But there is a case the port->lock is
not initialized by serial_core.  If the setup function for the console was
failed, it will not call uart_set_options() but the port is marked as
console (uart_console(port) returns 1).  It can happen if console was PCI
port which can not detected at the time of register_console.

This patch is to initialize port->lock for such console port.  With this
change, most of spin_lock_init() (some of them are labeled "Temporary
fix.") in low-level serial drivers can be omitted.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/serial/serial_core.c

@@ -2237,7 +2237,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 	 * If this port is a console, then the spinlock is already
 	 * initialised.
 	 */
-	if (!uart_console(port))
+	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED)))
 		spin_lock_init(&port->lock);
 
 	uart_configure_port(drv, state, port);