Fix a PHP 8.1 issue in lint rendering

Summary: Ref T13588. The lint renderer has some "strlen(null)" issues; correct them.

Test Plan: Hit lint messages under PHP 8.1.

Reviewers: 0

Subscribers: jeremy.norris, vostok4, vhbit, jaydiablo, 0

Maniphest Tasks: T13588

Differential Revision: https://secure.phabricator.com/D21743

src/lint/renderer/ArcanistConsoleLintRenderer.php

@@ -112,6 +112,8 @@ final class ArcanistConsoleLintRenderer extends ArcanistLintRenderer {
     $message = $message->newTrimmedMessage();
 
     $original = $message->getOriginalText();
+    $original = phutil_string_cast($original);
+
     $replacement = $message->getReplacementText();
 
     $line = $message->getLine();