constify dentry_operations: misc filesystems

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
index 85a30e9..e867ccf 100644
--- a/fs/adfs/dir.c
+++ b/fs/adfs/dir.c
@@ -263,7 +263,7 @@
 	return 0;
 }
 
-struct dentry_operations adfs_dentry_operations = {
+const struct dentry_operations adfs_dentry_operations = {
 	.d_hash		= adfs_hash,
 	.d_compare	= adfs_compare,
 };