Issue #2080303 by aaronott: Remove Unused local variable from...

Issue #2080303 by aaronott: Remove Unused local variable  from /core/modules/system/lib/Drupal/system/Tests/Database/LoggingTest.php.

core/modules/system/lib/Drupal/system/Tests/Database/LoggingTest.php

@@ -26,7 +26,7 @@ public static function getInfo() {
    * Tests that we can log the existence of a query.
    */
   function testEnableLogging() {
-    $log = Database::startLog('testing');
+    Database::startLog('testing');
 
     db_query('SELECT name FROM {test} WHERE age > :age', array(':age' => 25))->fetchCol();
     db_query('SELECT age FROM {test} WHERE name = :name', array(':name' => 'Ringo'))->fetchCol();