glib-init: fix redundant-decls of g_mem_gc_friendly

Currently g_mem_gc_friendly is declared in both gmem.h and glib-init.h
files, we will have reports on each unit that include these two files.

This patch removes the redundant declaration from glib-init.h

Since g_mem_gc_friendly is related to gmem.h and was first declared in
this header which also exports it via glib.h, then declare it in gmem.h

Other files already include gmem.h: garray.c and gslice.c, no need to
change anything.

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>

https://bugzilla.gnome.org/show_bug.cgi?id=710345

glib/glib-init.c

@@ -25,6 +25,7 @@
 
 #include "gutils.h"     /* for GDebugKey */
 #include "gconstructor.h"
+#include "gmem.h"       /* for g_mem_gc_friendly */
 
 #include <string.h>
 #include <stdlib.h>

glib/glib-init.h

@@ -26,7 +26,6 @@
 
 extern GLogLevelFlags g_log_always_fatal;
 extern GLogLevelFlags g_log_msg_prefix;
-GLIB_VAR gboolean g_mem_gc_friendly;
 
 #ifdef G_OS_WIN32
 #include <windows.h>