configfs: Constify ct_group_ops in struct config_item_type

Make 'ct_group_ops' const in struct config_item_type.
This allows constification of many structures which hold some function
pointers.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/6b720cf407e8a6d30f35beb72e031b2553d1ab7e.1761390472.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>

Author: tititiou36

fs/configfs/dir.c

@@ -598,7 +598,7 @@ static void detach_attrs(struct config_item * item)
 static int populate_attrs(struct config_item *item)
 {
 	const struct config_item_type *t = item->ci_type;
-	struct configfs_group_operations *ops;
+	const struct configfs_group_operations *ops;
 	struct configfs_attribute *attr;
 	struct configfs_bin_attribute *bin_attr;
 	int error = 0;

include/linux/configfs.h

@@ -65,7 +65,7 @@ extern void config_item_put(struct config_item *);
 struct config_item_type {
 	struct module				*ct_owner;
 	struct configfs_item_operations		*ct_item_ops;
-	struct configfs_group_operations	*ct_group_ops;
+	const struct configfs_group_operations	*ct_group_ops;
 	struct configfs_attribute		**ct_attrs;
 	struct configfs_bin_attribute		**ct_bin_attrs;
 };