usb: class: cdc-wdm: return the correct errno code

The "rv" is initialized to "-ENOMEM", because "rv" is re-assigned to
"-EINVAL", when kmalloc & usb_alloc_urb failed, the return value should
return "-ENOMEM" rather than "-EINVAL",so the "rv" assignment is placed
in the position where usb_endpoint_is_int_in is false.

Acked-by: Oliver Neukum <[e-mail]>
Signed-off-by: Junlin Yang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/class/cdc-wdm.c

···
 	INIT_WORK(&desc->rxwork, wdm_rxwork);
 	INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
 
-	rv = -EINVAL;
-	if (!usb_endpoint_is_int_in(ep))
+	if (!usb_endpoint_is_int_in(ep)) {
+		rv = -EINVAL;
 		goto err;
+	}
 
 	desc->wMaxPacketSize = usb_endpoint_maxp(ep);