Fix getMock FileCacheTest

tests/lib/Cache/FileCacheTest.php

@@ -21,6 +21,7 @@
  */
 
 namespace Test\Cache;
+use OC\Files\Storage\Local;
 
 /**
  * Class FileCacheTest
@@ -102,11 +103,10 @@ class FileCacheTest extends TestCache {
 	}
 
 	private function setupMockStorage() {
-		$mockStorage = $this->getMock(
-			'\OC\Files\Storage\Local',
-			['filemtime', 'unlink'],
-			[['datadir' => \OC::$server->getTempManager()->getTemporaryFolder()]]
-		);
+		$mockStorage = $this->getMockBuilder(Local::class)
+			->setMethods(['filemtime', 'unlink'])
+			->setConstructorArgs([['datadir' => \OC::$server->getTempManager()->getTemporaryFolder()]])
+			->getMock();
 
 		\OC\Files\Filesystem::mount($mockStorage, array(), '/test/cache');