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

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

If usb_otg_descriptor_alloc() failed, it need return ENOMEM.

Fixes: 578aa8a2b12c ("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.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>