USB: gadget: legacy: fix return error code in acm_ms_bind()

If usb_otg_descriptor_alloc() failed, it need return ENOMEM.

Fixes: 578aa8a2 ("usb: gadget: acm_ms: allocate and init otg descriptor by otg capabilities")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201117092955.4102785-1-yangyingliang@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/legacy/acm_ms.c

@@ -200,8 +200,10 @@ static int acm_ms_bind(struct usb_composite_dev *cdev)
 		struct usb_descriptor_header *usb_desc;
 
 		usb_desc = usb_otg_descriptor_alloc(gadget);
-		if (!usb_desc)
+		if (!usb_desc) {
+			status = -ENOMEM;
 			goto fail_string_ids;
+		}
 		usb_otg_descriptor_init(gadget, usb_desc);
 		otg_desc[0] = usb_desc;
 		otg_desc[1] = NULL;