Make this test work on Windows

Author: sebastianbergmann

tests/end-to-end/regression/5771.phpt

@@ -16,7 +16,7 @@ require_once __DIR__ . '/../../bootstrap.php';
 <testsuites>
   <testsuite name="PHPUnit\TestFixture\Issue5771\Issue5771Test" file="%sIssue5771Test.php" tests="1" assertions="0" errors="1" failures="0" skipped="0" time="%s">
     <testcase name="testOne" file="%sIssue5771Test.php" line="18" class="PHPUnit\TestFixture\Issue5771\Issue5771Test" classname="PHPUnit.TestFixture.Issue5771.Issue5771Test" assertions="0" time="%s">
-      <error type="PHPUnit\Framework\AssertionFailedError">PHPUnit\TestFixture\Issue5771\Issue5771Test::testOne
+      <error type="PHPUnit\Framework\AssertionFailedError">PHPUnit\TestFixture\Issue5771\Issue5771Test::testOne%A
 Test was run in child process and ended unexpectedly</error>
     </testcase>
   </testsuite>