Fix a fatal when viewing methods which no longer exist in the Conduit call log

Summary: Fixes T12252.

Test Plan:
I just faked this, but likely repro is:

  - Call method `x.y`.
  - Remove method `x.y` from the codebase.
  - View log.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12252

Differential Revision: https://secure.phabricator.com/D17342

src/applications/conduit/query/PhabricatorConduitLogSearchEngine.php

@@ -162,7 +162,7 @@ final class PhabricatorConduitLogSearchEngine
             ->addSigil('has-tooltip')
             ->setMetadata(
               array(
-                'tip' => pht('Unknown ("%s")', $status),
+                'tip' => pht('Unknown ("%s")', $method_status),
               ));
           break;
       }