ovl: mark *_cu_creds() as unused temporarily

They will become unused in the next patch and we'll drop them after the
conversion is finished together with the struct. This keeps the changes
small and reviewable.

Link: https://patch.msgid.link/20251114-work-ovl-cred-guard-copyup-v1-3-ea3fb15cf427@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

fs/overlayfs/copy_up.c

@@ -729,7 +729,7 @@ struct ovl_cu_creds {
 	struct cred *new;
 };
 
-static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc)
+static int __maybe_unused ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc)
 {
 	int err;
 
@@ -744,7 +744,7 @@ static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc)
 	return 0;
 }
 
-static void ovl_revert_cu_creds(struct ovl_cu_creds *cc)
+static void __maybe_unused ovl_revert_cu_creds(struct ovl_cu_creds *cc)
 {
 	if (cc->new) {
 		revert_creds(cc->old);