fix typo

Author: hfutatzhanghb

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirAttrOp.java

@@ -342,7 +342,7 @@ static INodeDirectory unprotectedSetQuota(
     if ((type != null) && (!fsd.isQuotaByStorageTypeEnabled() ||
         nsQuota != HdfsConstants.QUOTA_DONT_SET)) {
       throw new UnsupportedActionException(
-          "Failed to set quota by storage type because either " +
+          "Failed to set quota by storage type because either" +
           DFS_QUOTA_BY_STORAGETYPE_ENABLED_KEY + " is set to " +
           fsd.isQuotaByStorageTypeEnabled() + " or nsQuota value is illegal " +
           nsQuota);