pata_at91: fix ata_host_activate() failure handling

Add missing clk_put() call to ata_host_activate() failure path.

Sergei says,

  "Hm, I have once fixed that (see that *if* (!ret)) but looks like a
   later commit 477c87e90853d136b188c50c0e4a93d01cad872e (ARM:
   at91/pata: use gpio_is_valid to check the gpio) broke it again. :-(
   Would be good if the changelog did mention that..."

Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

drivers/ata/pata_at91.c

@@ -407,12 +407,13 @@ static int pata_at91_probe(struct platform_device *pdev)
 
 	host->private_data = info;
 
-	return ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
-			gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
-			irq_flags, &pata_at91_sht);
+	ret = ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
+				gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
+				irq_flags, &pata_at91_sht);
+	if (ret)
+		goto err_put;
 
-	if (!ret)
-		return 0;
+	return 0;
 
 err_put:
 	clk_put(info->mck);