jit: fix crash in memento_of_new_string_literal::make_debug_string

gcc/jit/ChangeLog:
	* jit-recording.c
	(gcc::jit::recording::memento_of_new_string_literal::make_debug_string):
	Add missing format string.

From-SVN: r219851

gcc/jit/ChangeLog

+2015-01-19  David Malcolm  <dmalcolm@redhat.com>
+
+	* jit-recording.c
+	(gcc::jit::recording::memento_of_new_string_literal::make_debug_string):
+	Add missing format string.
+
 2015-01-16  David Malcolm  <dmalcolm@redhat.com>
 
 	* Make-lang.in (lang_checks_parallelized): Add "check-jit".

gcc/jit/jit-recording.c

@@ -4012,6 +4012,7 @@ recording::string *
 recording::memento_of_new_string_literal::make_debug_string ()
 {
   return string::from_printf (m_ctxt,
+			      "%s",
 			      m_value->get_debug_string ());
 }