Remove unreachable code

The try/finally block will either return or throw.
Additionally, $socket was never defined.

Detected via static analysis

src/Symfony/Component/VarDumper/Server/Connection.php

@@ -91,7 +91,5 @@ class Connection
         } finally {
             restore_error_handler();
         }
-
-        return $socket;
     }
 }