iommu/vt-d: Zero out allocated memory in dmar_enable_qi

kmemcheck complained about the use of uninitialized memory.
Fix by using kzalloc instead of kmalloc.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJoerg Roedel <joro@8bytes.org>

drivers/iommu/dmar.c

@@ -1040,7 +1040,7 @@ int dmar_enable_qi(struct intel_iommu *iommu)
 
 	qi->desc = page_address(desc_page);
 
-	qi->desc_status = kmalloc(QI_LENGTH * sizeof(int), GFP_ATOMIC);
+	qi->desc_status = kzalloc(QI_LENGTH * sizeof(int), GFP_ATOMIC);
 	if (!qi->desc_status) {
 		free_page((unsigned long) qi->desc);
 		kfree(qi);