[glib] glib/gmessages.c: Use G_VA_COPY() instead of va_copy()

[Chun-wei Fan <fanchunwei src gnome org>]

commit c08b1a6ae561e58149c1c1d9fe17eaf8e7270452
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Jul 18 14:25:52 2016 +0800

    glib/gmessages.c: Use G_VA_COPY() instead of va_copy()
    
    Some compilers may not support va_copy(), so use the G_VA_COPY macro so
    that things can be supported properly on all supported compilers.

 glib/gmessages.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glib/gmessages.c b/glib/gmessages.c
index bcfe534..8cfdddf 100644
--- a/glib/gmessages.c
+++ b/glib/gmessages.c
@@ -1408,7 +1408,7 @@ g_log_structured (const gchar    *log_domain,
   priority = log_level_to_priority (log_level);
 
   /* Work out how many fields we have. */
-  va_copy (field_args, args);
+  G_VA_COPY (field_args, args);
 
   for (p = va_arg (args, gchar *), n_fields = 0;
        p != NULL;