adfs: constify adfs_dir_ops structures

The adfs_dir_ops structures are never modified, so declare them as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/adfs/dir_fplus.c b/fs/adfs/dir_fplus.c
index 82d14cd..c92cfb6 100644
--- a/fs/adfs/dir_fplus.c
+++ b/fs/adfs/dir_fplus.c
@@ -256,7 +256,7 @@
 	dir->sb = NULL;
 }
 
-struct adfs_dir_ops adfs_fplus_dir_ops = {
+const struct adfs_dir_ops adfs_fplus_dir_ops = {
 	.read		= adfs_fplus_read,
 	.setpos		= adfs_fplus_setpos,
 	.getnext	= adfs_fplus_getnext,