iommu/qcom: add missing put_device() call in qcom_iommu_of_xlate()

if of_find_device_by_node() succeed, qcom_iommu_of_xlate() doesn't have
a corresponding put_device(). Thus add put_device() to fix the exception
handling for this function implementation.

Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu")
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200929014037.2436663-1-yukuai3@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
index af6bec3..ef3dd32 100644
--- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c
+++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c
@@ -584,8 +584,10 @@
 	 * index into qcom_iommu->ctxs:
 	 */
 	if (WARN_ON(asid < 1) ||
-	    WARN_ON(asid > qcom_iommu->num_ctxs))
+	    WARN_ON(asid > qcom_iommu->num_ctxs)) {
+		put_device(&iommu_pdev->dev);
 		return -EINVAL;
+	}
 
 	if (!dev_iommu_priv_get(dev)) {
 		dev_iommu_priv_set(dev, qcom_iommu);
@@ -594,8 +596,10 @@
 		 * multiple different iommu devices.  Multiple context
 		 * banks are ok, but multiple devices are not:
 		 */
-		if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev)))
+		if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev))) {
+			put_device(&iommu_pdev->dev);
 			return -EINVAL;
+		}
 	}
 
 	return iommu_fwspec_add_ids(dev, &asid, 1);