net: fman: Unregister ethernet device on removal

When the mac device gets removed, it leaves behind the ethernet device.
This will result in a segfault next time the ethernet device accesses
mac_dev. Remove the ethernet device when we get removed to prevent
this. This is not completely reversible, since some resources aren't
cleaned up properly, but that can be addressed later.

Fixes: 39339616 ("fsl/fman: Add FMan MAC driver")
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20221103182831.2248833-1-sean.anderson@seco.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/fman/mac.c

@@ -487,12 +487,21 @@ static int mac_probe(struct platform_device *_of_dev)
 	return err;
 }
 
+static int mac_remove(struct platform_device *pdev)
+{
+	struct mac_device *mac_dev = platform_get_drvdata(pdev);
+
+	platform_device_unregister(mac_dev->priv->eth_dev);
+	return 0;
+}
+
 static struct platform_driver mac_driver = {
 	.driver = {
 		.name		= KBUILD_MODNAME,
 		.of_match_table	= mac_match,
 	},
 	.probe		= mac_probe,
+	.remove		= mac_remove,
 };
 
 builtin_platform_driver(mac_driver);