iommu/msm: Use BUG_ON instead of if () BUG()

Found by a coccicheck script.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/msm_iommu.c

@@ -106,8 +106,8 @@ static int __flush_iotlb(struct iommu_domain *domain)
 #endif
 
 	list_for_each_entry(ctx_drvdata, &priv->list_attached, attached_elm) {
-		if (!ctx_drvdata->pdev || !ctx_drvdata->pdev->dev.parent)
-			BUG();
+
+		BUG_ON(!ctx_drvdata->pdev || !ctx_drvdata->pdev->dev.parent);
 
 		iommu_drvdata = dev_get_drvdata(ctx_drvdata->pdev->dev.parent);
 		BUG_ON(!iommu_drvdata);