sh: intc: move to use bus_get_dev_root()

Direct access to the struct bus_type dev_root pointer is going away soon
so replace that with a call to bus_get_dev_root() instead, which is what
it is there for.

Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20230313182918.1312597-17-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/sh/intc/userimask.c

@@ -61,10 +61,18 @@ static DEVICE_ATTR(userimask, S_IRUSR | S_IWUSR,
 
 static int __init userimask_sysdev_init(void)
 {
+	struct device *dev_root;
+	int ret = 0;
+
 	if (unlikely(!uimask))
 		return -ENXIO;
 
-	return device_create_file(intc_subsys.dev_root, &dev_attr_userimask);
+	dev_root = bus_get_dev_root(&intc_subsys);
+	if (dev_root) {
+		ret = device_create_file(dev_root, &dev_attr_userimask);
+		put_device(dev_root);
+	}
+	return ret;
 }
 late_initcall(userimask_sysdev_init);