YARN-3956. Fix TestNodeManagerHardwareUtils fails on Mac (Varun Vasudev via wangda)

(cherry picked from commit 06e5dd2c84c49460884757b56980b1b9c58af996)

Conflicts:
	hadoop-yarn-project/CHANGES.txt

hadoop-yarn-project/CHANGES.txt

@@ -604,6 +604,8 @@ Release 2.8.0 - UNRELEASED
     YARN-3932. SchedulerApplicationAttempt#getResourceUsageReport and UserInfo 
     should based on total-used-resources. (Bibin A Chundatt via wangda)
 
+    YARN-3956. Fix TestNodeManagerHardwareUtils fails on Mac (Varun Vasudev via wangda)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/util/TestNodeManagerHardwareUtils.java

@@ -30,6 +30,11 @@ import org.mockito.Mockito;
 public class TestNodeManagerHardwareUtils {
 
   static class TestResourceCalculatorPlugin extends ResourceCalculatorPlugin {
+
+    TestResourceCalculatorPlugin() {
+      super(null);
+    }
+
     @Override
     public long getVirtualMemorySize() {
       return 0;