pcd: add error handling support for add_disk()

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/paride/pcd.c

@@ -941,9 +941,13 @@ static int pcd_init_unit(struct pcd_unit *cd, bool autoprobe, int port,
 	cd->present = 1;
 	pcd_probe_capabilities(cd);
 	register_cdrom(cd->disk, &cd->info);
-	add_disk(cd->disk);
+	ret = add_disk(cd->disk);
+	if (ret)
+		goto out_unreg_cdrom;
 	return 0;
 
+out_unreg_cdrom:
+	unregister_cdrom(&cd->info);
 out_pi_release:
 	pi_release(cd->pi);
 out_free_disk: