constify dentry_operations: rest

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/libfs.c b/fs/libfs.c
index 49b4409..ec600bd 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -44,7 +44,7 @@
  */
 struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 {
-	static struct dentry_operations simple_dentry_operations = {
+	static const struct dentry_operations simple_dentry_operations = {
 		.d_delete = simple_delete_dentry,
 	};