constify dentry_operations: misc filesystems

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index ad92461..ae881cc 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -1136,7 +1136,7 @@
 	return 1;
 }
 
-static struct dentry_operations xattr_lookup_poison_ops = {
+static const struct dentry_operations xattr_lookup_poison_ops = {
 	.d_compare = xattr_lookup_poison,
 };