usb: renesas_usbhs: remove callback when module removed.

The callback function which is called from platform must be removed
if module removed.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/usb/renesas_usbhs.h b/include/linux/usb/renesas_usbhs.h
index 565bca3..66bbdd1 100644
--- a/include/linux/usb/renesas_usbhs.h
+++ b/include/linux/usb/renesas_usbhs.h
@@ -143,7 +143,7 @@
 	({								\
 		struct renesas_usbhs_driver_callback *dc;		\
 		dc = &(renesas_usbhs_get_info(pdev)->driver_callback);	\
-		if (dc)							\
+		if (dc && dc->notify_hotplug)				\
 			dc->notify_hotplug(pdev);			\
 	})
 #endif /* RENESAS_USB_H */