iommu/dma: Remove redundant "!dev" checks

iommu_dma_init_domain() is now only called from iommu_setup_dma_ops(),
which has already assumed dev to be non-NULL.
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/06024523c080364390016550065e3cfe8031367e.1628682049.git.robin.murphy@arm.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/dma-iommu.c

@@ -370,7 +370,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 
 	init_iova_domain(iovad, 1UL << order, base_pfn);
 
-	if (!cookie->fq_domain && (!dev || !dev_is_untrusted(dev)) &&
+	if (!cookie->fq_domain && !dev_is_untrusted(dev) &&
 	    domain->ops->flush_iotlb_all && !iommu_get_dma_strict(domain)) {
 		if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
 					  iommu_dma_entry_dtor))
@@ -379,9 +379,6 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 			cookie->fq_domain = domain;
 	}
 
-	if (!dev)
-		return 0;
-
 	return iova_reserve_iommu_regions(dev, domain);
 }