drm/xe: Use ERR_CAST to return an error-valued pointer

Instead of directly casting and returning an error-valued pointer,
use ERR_CAST to make the error handling more explicit and improve
code clarity.

Signed-off-by: Yu Jiaoliang <[e-mail]>
Reviewed-by: Matthew Brost <[e-mail]>
Signed-off-by: Matthew Brost <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/xe/xe_sa.c

···
 	if (IS_ERR(bo)) {
 		drm_err(&xe->drm, "failed to allocate bo for sa manager: %ld\n",
 			PTR_ERR(bo));
-		return (struct xe_sa_manager *)bo;
+		return ERR_CAST(bo);
 	}
 	sa_manager->bo = bo;
 	sa_manager->is_iomem = bo->vmap.is_iomem;