HBASE-23645 Fixed remaining Checkstyle violations in hbase-common tests

Signed-off-by: Viraj Jasani <vjasani@apache.org>

Author: HorizonNet

hbase-checkstyle/src/main/resources/hbase/checkstyle-suppressions.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!DOCTYPE suppressions PUBLIC
-    "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
-    "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+        "https://checkstyle.org/dtds/suppressions_1_2.dtd">
 <!--
 /**
  * Licensed to the Apache Software Foundation (ASF) under one
@@ -42,4 +42,6 @@
   <suppress checks="IllegalImport" message="org\.apache\.htrace\.core"/>
   <suppress checks="ImportOrder" message="Extra separation in import group before"/>
   <suppress checks="MethodLength" files="org.apache.hadoop.hbase.thrift.DemoClient.java"/>
+  <suppress checks="InnerAssignment" files="org.apache.hadoop.hbase.Waiter"/>
+  <suppress checks="EmptyBlock" files="org.apache.hadoop.hbase.TestTimeout"/>
 </suppressions>