zd1201: use kzalloc

Use kzalloc instead of kmalloc + memset.

The semantic patch that makes this change is:
(https://coccinelle.gitlabpages.inria.fr/website/

)

//<smpl>
@@
expression res, size, flag;
@@
- res = kmalloc(size, flag);
+ res = kzalloc(size, flag);
  ...
- memset(res, 0, size);
//</smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220312102705.71413-6-Julia.Lawall@inria.fr