ipack: Fail earlier for drivers without probe function

A driver without a probe function isn't useful as it can never be used.
Let registering such a driver fail already instead of failing every
binding.

This is only cosmetic as there is no ipack driver without a probe function.

Signed-off-by: Uwe Kleine-König <[e-mail]>
Acked-by: Samuel Iglesias Gonsalvez <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/ipack/ipack.c

···
 	struct ipack_device *dev = to_ipack_dev(device);
 	struct ipack_driver *drv = to_ipack_driver(device->driver);
 
-	if (!drv->ops->probe)
-		return -EINVAL;
-
 	return drv->ops->probe(dev);
 }
 
···
 int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
 			  const char *name)
 {
+	if (!edrv->ops->probe)
+		return -EINVAL;
+
 	edrv->driver.owner = owner;
 	edrv->driver.name = name;
 	edrv->driver.bus = &ipack_bus_type;