drm/radeon: use kzalloc for allocating one thing

Use kzalloc for allocating one thing rather than
kcalloc(1...

The semantic patch that makes this change is as follows:

// <smpl>
@@
@@

- kcalloc(1,
+ kzalloc(
          ...)
// </smpl>
Signed-off-by: NManinder Singh <maninder1.s@samsung.com>
Reviewed-by: NVaneet Narang <v.narang@samsung.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -719,7 +719,7 @@ static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
 		return 0;
 
 	if (gtt && gtt->userptr) {
-		ttm->sg = kcalloc(1, sizeof(struct sg_table), GFP_KERNEL);
+		ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
 		if (!ttm->sg)
 			return -ENOMEM;