bcachefs: fix setting btree_node_accessed()

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_cache.c

@@ -748,7 +748,7 @@ struct btree *bch2_btree_node_get(struct bch_fs *c, struct btree_iter *iter,
 	}
 
 	/* avoid atomic set bit if it's not needed: */
-	if (btree_node_accessed(b))
+	if (!btree_node_accessed(b))
 		set_btree_node_accessed(b);
 
 	if (unlikely(btree_node_read_error(b))) {