gmessages: Simplify _g_log_abort() in gmessages.c a little
gmessages: Simplify _g_log_abort() in gmessages.c a little

https://bugzilla.gnome.org/show_bug.cgi?id=744456

johne53/MB3Glib,endlessm/glib,endlessm/glib,endlessm/glib,johne53/MB3Glib,johne53/MB3Glib,johne53/MB3Glib,johne53/MB3Glib,johne53/MB3Glib,endlessm/glib,endlessm/glib