[planners] fix clippy warning
@@ -42,7 +42,7 @@ impl PlanScheduler {
let mut results = vec![];
let cluster = ctx.try_get_cluster()?;
let cluster_nodes = cluster.get_nodes()?;
- let cluster_nums = if cluster_nodes.len() == 0 {
+ let cluster_nums = if cluster_nodes.is_empty() {
1
} else {
cluster_nodes.len()
