mips: txx9: fix iounmap related issue

if device_register return error, iounmap should be called, also iounmap
need to call before put_device.

Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
Reviewed-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20476/
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org

arch/mips/txx9/generic/setup.c

@@ -960,12 +960,11 @@ void __init txx9_sramc_init(struct resource *r)
 		goto exit_put;
 	err = sysfs_create_bin_file(&dev->dev.kobj, &dev->bindata_attr);
 	if (err) {
-		device_unregister(&dev->dev);
 		iounmap(dev->base);
-		kfree(dev);
+		device_unregister(&dev->dev);
 	}
 	return;
 exit_put:
+	iounmap(dev->base);
 	put_device(&dev->dev);
-	return;
 }