usb: gadget: storage: release superspeed descriptors.

Release superspeed mass storage descriptors memory
when the function is unbind.

Signed-off-by: Yu Xu <yuxu@marvell.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_mass_storage.c

@@ -2975,6 +2975,7 @@ static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
 	fsg_common_put(common);
 	usb_free_descriptors(fsg->function.descriptors);
 	usb_free_descriptors(fsg->function.hs_descriptors);
+	usb_free_descriptors(fsg->function.ss_descriptors);
 	kfree(fsg);
 }