drm/msm: Fix potential invalid ptr free

The error path cleanup expects that chain and syncobj are either NULL or
valid pointers.  But post_deps was not allocated with __GFP_ZERO.

Fixes: ab723b7a ("drm/msm: Add syncobj support.")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Patchwork: https://patchwork.freedesktop.org/patch/523051/
Link: https://lore.kernel.org/r/20230215235048.1166484-1-robdclark@gmail.com

drivers/gpu/drm/msm/msm_gem_submit.c

@@ -637,7 +637,7 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
 	int ret = 0;
 	uint32_t i, j;
 
-	post_deps = kmalloc_array(nr_syncobjs, sizeof(*post_deps),
+	post_deps = kcalloc(nr_syncobjs, sizeof(*post_deps),
 			    GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
 	if (!post_deps)
 		return ERR_PTR(-ENOMEM);
@@ -653,7 +653,6 @@ static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
 		}
 
 		post_deps[i].point = syncobj_desc.point;
-		post_deps[i].chain = NULL;
 
 		if (syncobj_desc.flags) {
 			ret = -EINVAL;