[gnome-settings-daemon] tests: Simplify Xorg check

[Bastien Nocera <hadess src gnome org>]

commit 37ecf4f5840e1ac7dafe0270599b6e5bc4e56059
Author: Bastien Nocera <hadess hadess net>
Date:   Fri Jul 5 16:40:12 2013 +0200

    tests: Simplify Xorg check

 tests/gsdtestcase.py |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/tests/gsdtestcase.py b/tests/gsdtestcase.py
index df2159d..23a5141 100644
--- a/tests/gsdtestcase.py
+++ b/tests/gsdtestcase.py
@@ -14,6 +14,8 @@ import shutil
 import sys
 from glob import glob
 
+from gi.repository import GLib
+
 try:
     import dbusmock
 except ImportError:
@@ -185,9 +187,8 @@ class GSDTestCase(dbusmock.DBusTestCase):
 
         # some distros like Fedora install Xorg as suid root; copy it into our
         # workdir to drop the suid bit and run it as user
-        which = subprocess.Popen(['which', 'Xorg'], stdout=subprocess.PIPE)
-        out = which.communicate()[0].strip()
-        if which.returncode != 0 or not out:
+        out = GLib.find_program_in_path ('Xorg')
+        if not out:
             sys.stderr.write('ERROR: Xorg not installed\n')
             sys.exit(1)
         xorg = os.path.join(klass.workdir, 'Xorg')