ata: ahci-dwc: Simplify with scoped for each OF child loop

Use scoped for-each loop when iterating over device nodes and switch to
iterating already over available nodes to make code a bit simpler.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

Author: krzk

drivers/ata/ahci_dwc.c

@@ -260,7 +260,6 @@ static void ahci_dwc_init_timer(struct ahci_host_priv *hpriv)
 static int ahci_dwc_init_dmacr(struct ahci_host_priv *hpriv)
 {
 	struct ahci_dwc_host_priv *dpriv = hpriv->plat_data;
-	struct device_node *child;
 	void __iomem *port_mmio;
 	u32 port, dmacr, ts;
 
@@ -271,14 +270,9 @@ static int ahci_dwc_init_dmacr(struct ahci_host_priv *hpriv)
 	 * the HBA global reset so we can freely initialize it once until the
 	 * next system reset.
 	 */
-	for_each_child_of_node(dpriv->pdev->dev.of_node, child) {
-		if (!of_device_is_available(child))
-			continue;
-
-		if (of_property_read_u32(child, "reg", &port)) {
-			of_node_put(child);
+	for_each_available_child_of_node_scoped(dpriv->pdev->dev.of_node, child) {
+		if (of_property_read_u32(child, "reg", &port))
 			return -EINVAL;
-		}
 
 		port_mmio = __ahci_port_base(hpriv, port);
 		dmacr = readl(port_mmio + AHCI_DWC_PORT_DMACR);