drm/ttm: use kvcalloc() instead of kvmalloc_array() in ttm_tt v2

simplify programming with existing functions.

v2 (chk): minimal coding style cleanup
Signed-off-by: Yang Wang <KevinYang.Wang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421123442.1834102-1-KevinYang.Wang@amd.comSigned-off-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/ttm/ttm_tt.c

@@ -96,19 +96,17 @@ int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
  */
 static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
 {
-	ttm->pages = kvmalloc_array(ttm->num_pages, sizeof(void*),
-			GFP_KERNEL | __GFP_ZERO);
+	ttm->pages = kvcalloc(ttm->num_pages, sizeof(void*), GFP_KERNEL);
 	if (!ttm->pages)
 		return -ENOMEM;
+
 	return 0;
 }
 
 static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
 {
-	ttm->pages = kvmalloc_array(ttm->num_pages,
-				    sizeof(*ttm->pages) +
-				    sizeof(*ttm->dma_address),
-				    GFP_KERNEL | __GFP_ZERO);
+	ttm->pages = kvcalloc(ttm->num_pages, sizeof(*ttm->pages) +
+			      sizeof(*ttm->dma_address), GFP_KERNEL);
 	if (!ttm->pages)
 		return -ENOMEM;
 
@@ -118,11 +116,11 @@ static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
 
 static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
 {
-	ttm->dma_address = kvmalloc_array(ttm->num_pages,
-					  sizeof(*ttm->dma_address),
-					  GFP_KERNEL | __GFP_ZERO);
+	ttm->dma_address = kvcalloc(ttm->num_pages, sizeof(*ttm->dma_address),
+				    GFP_KERNEL);
 	if (!ttm->dma_address)
 		return -ENOMEM;
+
 	return 0;
 }