USB: Turn usb_resume_both() into static inline

drivers/usb/core/hub.c: In function `hub_events':
drivers/usb/core/hub.c:2591: warning: statement with no effect
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/usb.h

@@ -40,7 +40,10 @@ extern int usb_port_resume(struct usb_device *dev);
 #else
 
 #define usb_suspend_both(udev, msg)	0
-#define usb_resume_both(udev)		0
+static inline int usb_resume_both(struct usb_device *udev)
+{
+	return 0;
+}
 #define usb_port_suspend(dev)		0
 #define usb_port_resume(dev)		0