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: Maninder Singh <[e-mail]>
Reviewed-by: Vaneet Narang <[e-mail]>
Reviewed-by: Christian König <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/radeon/radeon_ttm.c

···
 		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;