HDFS-15256. Fix typo in DataXceiverServer#run(). Contributed by Lisheng Sun.

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

@@ -229,7 +229,7 @@ class DataXceiverServer implements Runnable {
         int curXceiverCount = datanode.getXceiverCount();
         if (curXceiverCount > maxXceiverCount) {
           throw new IOException("Xceiver count " + curXceiverCount
-              + " exceeds the limit of concurrent xcievers: "
+              + " exceeds the limit of concurrent xceivers: "
               + maxXceiverCount);
         }