paths: remove DEV_NULL

The platform-specific path to /dev/null is provided by the Python standard
library in os.devnull.

Replace all uses of paths.DEV_NULL with os.devnull and remove DEV_NULL.

https://fedorahosted.org/freeipa/ticket/6474

Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>

ipaclient/install/client.py

@@ -1083,7 +1083,7 @@ def configure_sshd_config(fstore, options):
         )
 
         for candidate in candidates:
-            args = ['sshd', '-t', '-f', paths.DEV_NULL]
+            args = ['sshd', '-t', '-f', os.devnull]
             for item in candidate.items():
                 args.append('-o')
                 args.append('%s=%s' % item)

ipaplatform/base/paths.py

@@ -33,7 +33,6 @@ class BasePathNamespace(object):
     SYSTEMCTL = "/bin/systemctl"
     TAR = "/bin/tar"
     BIN_TRUE = "/bin/true"
-    DEV_NULL = "/dev/null"
     DEV_STDIN = "/dev/stdin"
     AUTOFS_LDAP_AUTH_CONF = "/etc/autofs_ldap_auth.conf"
     ETC_DIRSRV = "/etc/dirsrv"

ipapython/ipautil.py

@@ -413,7 +413,7 @@ def run(args, stdin=None, raiseonerr=True, nolog=(), env=None,
     if stdin:
         p_in = subprocess.PIPE
     if skip_output:
-        p_out = p_err = open(paths.DEV_NULL, 'w')
+        p_out = p_err = open(os.devnull, 'w')
     elif redirect_output:
         p_out = sys.stdout
         p_err = sys.stderr