HDFS-13591. TestDFSShell#testSetrepLow fails on Windows. Contributed by Anbang Hu.

(cherry picked from commit 9dbf4f01665d5480a70395a24519cbab5d4db0c5)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSShell.java

@@ -2675,11 +2675,11 @@ public void testSetrepLow() throws Exception {
         System.setErr(origErr);
       }
 
-      assertEquals("Error message is not the expected error message",
-          "setrep: Requested replication factor of 1 is less than "
-              + "the required minimum of 2 for /tmp/TestDFSShell-"
-              + "testSetrepLow/testFileForSetrepLow\n",
-          bao.toString());
+      assertTrue("Error message is not the expected error message"
+          + bao.toString(), bao.toString().startsWith(
+              "setrep: Requested replication factor of 1 is less than "
+                  + "the required minimum of 2 for /tmp/TestDFSShell-"
+                  + "testSetrepLow/testFileForSetrepLow"));
     } finally {
       shell.close();
       cluster.shutdown();