Avoid two warnings in tools/widl/parser.y (RESEND)

[Gerald Pfeifer]

This has been triggering warnings with GCC 4.5.

Gerald

ChangeLog:
Initialize two variables in the default/assert(0) case.

diff --git a/tools/widl/parser.y b/tools/widl/parser.y
index dda4a37..992c205 100644
--- a/tools/widl/parser.y
+++ b/tools/widl/parser.y
@@ -2346,6 +2346,7 @@ static void check_field_common(const type_t *container_type,
         break;
     default:
         /* should be no other container types */
+        container_type_name = var_type = NULL;
         assert(0);
     }