USB: remove fake "address-of" expressions

Fake "address-of" expressions that evaluate to NULL generally confuse
readers and can provoke compiler warnings.  This patch (as1412)
removes three such fake expressions, using "#ifdef"s in their place.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/usb.c

@@ -317,10 +317,6 @@ static const struct dev_pm_ops usb_device_pm_ops = {
 	.restore =	usb_dev_restore,
 };
 
-#else
-
-#define usb_device_pm_ops	(*(struct dev_pm_ops *) NULL)
-
 #endif	/* CONFIG_PM */
 
 
@@ -338,7 +334,9 @@ struct device_type usb_device_type = {
 	.release =	usb_release_dev,
 	.uevent =	usb_dev_uevent,
 	.devnode = 	usb_devnode,
+#ifdef CONFIG_PM
 	.pm =		&usb_device_pm_ops,
+#endif
 };