minor #5171 Fix test (SpacePossum)

This PR was merged into the 3.0 branch.

Discussion
----------

Fix test

Commits
-------

d3a9fec84 Fix test

tests/Differ/TestSplFileInfo.php → tests/Differ/DummyTestSplFileInfo.php

@@ -12,7 +12,7 @@
 
 namespace PhpCsFixer\Tests\Differ;
 
-final class TestSplFileInfo extends \SplFileInfo
+final class DummyTestSplFileInfo extends \SplFileInfo
 {
     public function getRealPath()
     {

tests/Differ/UnifiedDifferTest.php

@@ -54,7 +54,7 @@ final class UnifiedDifferTest extends AbstractDifferTestCase
 -a
 +b
 ',
-            $differ->diff("a\n", "b\n", new TestSplFileInfo('/foo/bar/test test test.txt'))
+            $differ->diff("a\n", "b\n", new DummyTestSplFileInfo('/foo/bar/test test test.txt'))
         );
     }
 }