HBASE-15519 Add per-user metrics with lossy counting (addendum)

Author: petersomogyi

hbase-hadoop2-compat/src/test/java/org/apache/hadoop/hbase/regionserver/TestMetricsUserSourceImpl.java

@@ -37,6 +37,7 @@ public class TestMetricsUserSourceImpl {
   public static final HBaseClassTestRule CLASS_RULE =
       HBaseClassTestRule.forClass(TestMetricsUserSourceImpl.class);
 
+  @SuppressWarnings("SelfComparison")
   @Test
   public void testCompareToHashCodeEquals() throws Exception {
     MetricsRegionServerSourceFactory fact