[glib] Avoid a leak for arguments in va_list marshallers

[Emmanuele Bassi <ebassi src gnome org>]

commit 30b961607a187c2e55cadc73db96ec99d3d8a44b
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Jul 11 12:24:10 2017 +0100

    Avoid a leak for arguments in va_list marshallers
    
    We need to revers a check on whether the list of arguments needs
    unboxing.

 gobject/glib-genmarshal.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gobject/glib-genmarshal.in b/gobject/glib-genmarshal.in
index fd10870..eb473d5 100755
--- a/gobject/glib-genmarshal.in
+++ b/gobject/glib-genmarshal.in
@@ -733,7 +733,7 @@ def generate_body(retval, params, prefix, va_marshal=False):
 
     if va_marshal:
         boxed_args = [x for x in get_args if IN_ARGS[x].get('box', None) is not None]
-        if boxed_args:
+        if not boxed_args:
             body += ['']
         else:
             for idx, arg in enumerate(get_args):