PM: Fix misuse of wakeup flag accessors in serial core

This patch (as1059) fixes a mistake in the way the serial core
initializes a device's wakeup settings.  It should use the accessor
routine instead of relying on a macro producing an lvalue.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index c32c1ca..a9ca03e 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2422,7 +2422,7 @@
 	 */
 	tty_dev = tty_register_device(drv->tty_driver, port->line, port->dev);
 	if (likely(!IS_ERR(tty_dev))) {
-		device_can_wakeup(tty_dev) = 1;
+		device_init_wakeup(tty_dev, 1);
 		device_set_wakeup_enable(tty_dev, 0);
 	} else
 		printk(KERN_ERR "Cannot register tty device on line %d\n",