Corrections from PR review for DB2SchemaManager and related test

lib/Doctrine/DBAL/Schema/DB2SchemaManager.php

@@ -41,9 +41,7 @@ class DB2SchemaManager extends AbstractSchemaManager
 
         $tables = $this->_conn->fetchAll($sql);
 
-        $tableNames = $this->_getPortableTablesList($tables);
-
-        return $this->filterAssetNames($tableNames);
+        return $this->filterAssetNames($this->_getPortableTablesList($tables));
     }
 
     /**

tests/Doctrine/Tests/DBAL/Schema/DB2SchemaManagerTest.php

@@ -15,7 +15,7 @@ use Doctrine\DBAL\Schema\DB2SchemaManager;
 final class DB2SchemaManagerTest extends \PHPUnit_Framework_TestCase
 {
     /**
-     * @var Connection
+     * @var Connection|\PHPUnit_Framework_MockObject_MockObject
      */
     private $conn;
 
@@ -37,6 +37,11 @@ final class DB2SchemaManagerTest extends \PHPUnit_Framework_TestCase
         $this->manager = new DB2SchemaManager($this->conn);
     }
 
+    /**
+     * @group DBAL-2701
+     * @see https://github.com/doctrine/dbal/issues/2701
+     * @return void
+     */
     public function testListTableNamesFiltersAssetNamesCorrectly()
     {
         $this->conn->getConfiguration()->setFilterSchemaAssetsExpression('/^(?!T_)/');