drivers: tty: serial: sb1250-duart: fix missing parentheses

Fix checkpatch warning:

    ERROR: Macros with complex values should be enclosed in parentheses
    torvalds#911: FILE: drivers/tty/serial/sb1250-duart.c:911:
    +#define SERIAL_SB1250_DUART_CONSOLE	&sbd_console

Signed-off-by: Enrico Weigelt <info@metux.net>

drivers/tty/serial/sb1250-duart.c

@@ -904,7 +904,7 @@ static int __init sbd_serial_console_init(void)
 
 console_initcall(sbd_serial_console_init);
 
-#define SERIAL_SB1250_DUART_CONSOLE	&sbd_console
+#define SERIAL_SB1250_DUART_CONSOLE	(&sbd_console)
 #else
 #define SERIAL_SB1250_DUART_CONSOLE	NULL
 #endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */