HDFS-14324. Fix TestDataNodeVolumeFailure. Contributed by Ayush Saxena.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeVolumeFailure.java

@@ -308,6 +308,7 @@ public class TestDataNodeVolumeFailure {
 
     // DN0 should stop after the number of failure disks exceed tolerated
     // value (1).
+    dn0.checkDiskError();
     assertFalse(dn0.shouldRun());
   }