HDFS-13618. Fix TestDataNodeFaultInjector test failures on Windows. Contributed by Xiao Liang.

(cherry picked from commit a8e9ee3fdf3aa1b889dfdd3bade91ba754ed9ee1)

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

@@ -118,7 +118,7 @@ public class TestDataNodeFaultInjector {
       final MetricsDataNodeFaultInjector mdnFaultInjector) throws Exception {
 
     final Path baseDir = new Path(
-        PathUtils.getTestDir(getClass()).getAbsolutePath(),
+        PathUtils.getTestDir(getClass()).getPath(),
         GenericTestUtils.getMethodName());
     final DataNodeFaultInjector oldDnInjector = DataNodeFaultInjector.get();
     DataNodeFaultInjector.set(mdnFaultInjector);