HDFS-16361. Fix log format for QueryCommand (#3732). Contributed by tomscut.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/diskbalancer/command/QueryCommand.java

@@ -84,7 +84,7 @@ public class QueryCommand extends Command {
         System.out.printf("%s", workStatus.currentStateString());
       }
     } catch (DiskBalancerException ex) {
-      LOG.error("Query plan failed. ex: {}", ex);
+      LOG.error("Query plan failed.", ex);
       throw ex;
     }
   }