HDFS-16901: Minor fix for unit test.

Signed-off-by: Owen O'Malley <oomalley@linkedin.com>

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpc.java

@@ -2090,7 +2090,7 @@ public class TestRouterRpc {
   public void testRealUserPropagationInCallerContext()
       throws IOException, InterruptedException {
     GenericTestUtils.LogCapturer auditlog =
-        GenericTestUtils.LogCapturer.captureLogs(FSNamesystem.auditLog);
+        GenericTestUtils.LogCapturer.captureLogs(FSNamesystem.AUDIT_LOG);
 
     // Current callerContext is null
     assertNull(CallerContext.getCurrent());