[glib] Fix build on old kernels

[Matthias Clasen <matthiasc src gnome org>]

commit 9686d82daf9c2082fa5d3055ac5b777490a95dc0
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jan 4 09:38:14 2011 -0500

    Fix build on old kernels
    
    Cope with BTRFS_SUPER_MAGIC not being defined.

 glib/gfileutils.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glib/gfileutils.c b/glib/gfileutils.c
index fff6492..a87f0e9 100644
--- a/glib/gfileutils.c
+++ b/glib/gfileutils.c
@@ -968,7 +968,7 @@ write_to_temp_file (const gchar  *contents,
       goto out;
     }
 
-#ifdef __linux__
+#ifdef BTRFS_SUPER_MAGIC
   {
     struct statfs buf;