iommu/exynos: fix device leak on of_xlate()

Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during of_xlate().

Note that commit 1a26044954a6 ("iommu/exynos: add missing put_device()
call in exynos_iommu_of_xlate()") fixed the leak in a couple of error
paths, but the reference is still leaking on success.

Fixes: aa759fd376fb ("iommu/exynos: Add callback for initializing devices from device tree")
Cc: [e-mail] # 4.2: 1a26044954a6
Cc: Yu Kuai <[e-mail]>
Acked-by: Robin Murphy <[e-mail]>
Acked-by: Marek Szyprowski <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>
Signed-off-by: Joerg Roedel <[e-mail]>

drivers/iommu/exynos-iommu.c

···
 		return -ENODEV;
 
 	data = platform_get_drvdata(sysmmu);
-	if (!data) {
-		put_device(&sysmmu->dev);
+	put_device(&sysmmu->dev);
+	if (!data)
 		return -ENODEV;
-	}
 
 	if (!owner) {
 		owner = kzalloc(sizeof(*owner), GFP_KERNEL);
-		if (!owner) {
-			put_device(&sysmmu->dev);
+		if (!owner)
 			return -ENOMEM;
-		}
 
 		INIT_LIST_HEAD(&owner->controllers);
 		mutex_init(&owner->rpm_lock);