[gobject-introspection] giscanner/utils.py: Fix on non-UNIX-like platforms

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

commit e8f39a0a2408898e8a36e9011705c7a55f115afc
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Thu Jun 15 09:03:38 2017 +0800

    giscanner/utils.py: Fix on non-UNIX-like platforms
    
    Commit 85b1d70b93211415d975deff6050f1401743e72d changed the null device
    from the platform-independent os.devnull to the UNIX /dev/null, which
    broke introspection builds on non-UNIX-like platforms, as /dev/null is a
    notion that does not exist on those platforms.  Fix this by changing
    back to os.devnull, but still opening it as writable.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=781312

 giscanner/utils.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/giscanner/utils.py b/giscanner/utils.py
index da848d5..df512d7 100644
--- a/giscanner/utils.py
+++ b/giscanner/utils.py
@@ -159,7 +159,7 @@ def get_libtool_command(options):
         libtool_cmd = 'glibtool'
     try:
         subprocess.check_call([libtool_cmd, '--version'],
-                              stdout=open('/dev/null', 'w'))
+                              stdout=open(os.devnull, 'w'))
     except (subprocess.CalledProcessError, OSError):
         # If libtool's not installed, assume we don't need it
         return None