iommu/vt-d: release invalidation queue when destroying IOMMU unit

Release associated invalidation queue when destroying IOMMU unit
to avoid memory leak.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

drivers/iommu/dmar.c

@@ -737,6 +737,12 @@ static void free_iommu(struct intel_iommu *iommu)
 		destroy_irq(iommu->irq);
 	}
 
+	if (iommu->qi) {
+		free_page((unsigned long)iommu->qi->desc);
+		kfree(iommu->qi->desc_status);
+		kfree(iommu->qi);
+	}
+
 	if (iommu->reg)
 		unmap_iommu(iommu);