mfd: Fix tps6586x_add_subdevs error path

1. return -ENOMEM if platform_device_alloc() fail.
2. call platform_device_put() if platform_device_add() fail.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/tps6586x.c

@@ -273,13 +273,19 @@ static int __devinit tps6586x_add_subdevs(struct tps6586x *tps6586x,
 		subdev = &pdata->subdevs[i];
 
 		pdev = platform_device_alloc(subdev->name, subdev->id);
+		if (!pdev) {
+			ret = -ENOMEM;
+			goto failed;
+		}
 
 		pdev->dev.parent = tps6586x->dev;
 		pdev->dev.platform_data = subdev->platform_data;
 
 		ret = platform_device_add(pdev);
-		if (ret)
+		if (ret) {
+			platform_device_put(pdev);
 			goto failed;
+		}
 	}
 	return 0;