power: reset: hisi-reboot: Unmap region obtained by of_iomap

Free memory mapping, if probe is not successful.

Fixes: 4a9b37371822 ("power: reset: move hisilicon reboot code")
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
diff --git a/drivers/power/reset/hisi-reboot.c b/drivers/power/reset/hisi-reboot.c
index 9ab7f56..f69387e 100644
--- a/drivers/power/reset/hisi-reboot.c
+++ b/drivers/power/reset/hisi-reboot.c
@@ -53,13 +53,16 @@
 
 	if (of_property_read_u32(np, "reboot-offset", &reboot_offset) < 0) {
 		pr_err("failed to find reboot-offset property\n");
+		iounmap(base);
 		return -EINVAL;
 	}
 
 	err = register_restart_handler(&hisi_restart_nb);
-	if (err)
+	if (err) {
 		dev_err(&pdev->dev, "cannot register restart handler (err=%d)\n",
 			err);
+		iounmap(base);
+	}
 
 	return err;
 }