iommu/vt-d: Fix leaked ioremap mapping

iommu_load_old_irte() appears to leak the old_irte mapping after use.

Cc: Joerg Roedel <jroedel@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/intel_irq_remapping.c

@@ -426,6 +426,8 @@ static int iommu_load_old_irte(struct intel_iommu *iommu)
 			bitmap_set(iommu->ir_table->bitmap, i, 1);
 	}
 
+	iounmap(old_ir_table);
+
 	return 0;
 }