iommu/sun50i: Use __GFP_ZERO instead of memset()

Allocate zeroed memory so there is no need to memset it to 0 in the
driver.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Cc: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20200514124621.25999-2-joro@8bytes.org

drivers/iommu/sun50i-iommu.c

@@ -616,11 +616,10 @@ static struct iommu_domain *sun50i_iommu_domain_alloc(unsigned type)
 	    iommu_get_dma_cookie(&sun50i_domain->domain))
 		goto err_free_domain;
 
-	sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL,
+	sun50i_domain->dt = (u32 *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
 						    get_order(DT_SIZE));
 	if (!sun50i_domain->dt)
 		goto err_put_cookie;
-	memset(sun50i_domain->dt, 0, DT_SIZE);
 
 	refcount_set(&sun50i_domain->refcnt, 1);