HDFS-14407. Fix misuse of SLF4j logging API in DatasetVolumeChecker#checkAllVolumes. Contributed by Wanqiang Ji.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/checker/DatasetVolumeChecker.java

@@ -242,7 +242,7 @@ public class DatasetVolumeChecker {
     // Wait until our timeout elapses, after which we give up on
     // the remaining volumes.
     if (!latch.await(maxAllowedTimeForCheckMs, TimeUnit.MILLISECONDS)) {
-      LOG.warn("checkAllVolumes timed out after {} ms" +
+      LOG.warn("checkAllVolumes timed out after {} ms",
           maxAllowedTimeForCheckMs);
     }