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 <uwe@kleine-koenig.org>
Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Link: https://lore.kernel.org/r/20210207215556.96371-1-uwe@kleine-koenig.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/ipack/ipack.c

@@ -64,9 +64,6 @@ static int ipack_bus_probe(struct device *device)
 	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);
 }
 
@@ -252,6 +249,9 @@ EXPORT_SYMBOL_GPL(ipack_bus_unregister);
 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;