ACPI: property: Rework acpi_graph_get_next_endpoint()

Rework the code obtaining the next endpoint in
acpi_graph_get_next_endpoint(). The resulting code removes unnecessary
contitionals and should be easier to follow.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://patch.msgid.link/20251001104320.1272752-4-sakari.ailus@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Sakari Ailus

drivers/acpi/property.c

@@ -1491,14 +1491,17 @@ static struct fwnode_handle *acpi_graph_get_next_endpoint(
 	if (!port)
 		return NULL;
 
-	endpoint = acpi_get_next_subnode(port, prev);
-	while (!endpoint) {
-		port = acpi_get_next_subnode(fwnode, port);
-		if (!port)
+	do {
+		endpoint = acpi_get_next_subnode(port, prev);
+		if (endpoint)
 			break;
-		if (is_acpi_graph_node(port, "port"))
-			endpoint = acpi_get_next_subnode(port, NULL);
-	}
+
+		prev = NULL;
+
+		do {
+			port = acpi_get_next_subnode(fwnode, port);
+		} while (port && !is_acpi_graph_node(port, "port"));
+	} while (port);
 
 	/*
 	 * The names of the endpoint nodes begin with "endpoint@" followed by