tests: fix strings test

For non udev path use DM_DEFAULT_NAME_MANGLING_MODE.
Skip this test when using real /dev dir, since udev is not able
to create such device name unless mangled...

test/shell/mdata-strings.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-# Copyright (C) 2008-2011 Red Hat, Inc. All rights reserved.
+# Copyright (C) 2008-2013 Red Hat, Inc. All rights reserved.
 #
 # This copyrighted material is made available to anyone wishing to use,
 # modify, copy, or redistribute it subject to the terms and conditions
@@ -13,10 +13,15 @@
 
 . lib/test
 
-aux prepare_devs 2
-aux lvmconf 'devices/global_filter = [ "a|.*dev/mapper/.*LVMTEST.*pv[0-9_]*$|", "r|.*|" ]'
+# For udev impossible to create
+test "$LVM_TEST_DEVDIR" = "/dev" && skip
+
+aux prepare_devs 2
+aux extend_filter_LVMTEST
+
+# Setup mangling to 'none' globaly for all libdm users
+export DM_DEFAULT_NAME_MANGLING_MODE=none
 
-# for udev impossible to create
 pv_ugly="__\"!@#\$%^&*,()|@||'\\\"__pv1"
 
 # 'set up temp files, loopback devices'
@@ -30,7 +35,8 @@ dm_table | grep -F "$pv_ugly"
 created="$dev1"
 # when used with real udev without fallback, it will fail here
 pvcreate "$dev1" || created="$dev2"
-pvdisplay | should grep -F "$pv_ugly"
+pvdisplay 2>&1 | tee >err
+should grep -F "$pv_ugly" err
 should check pv_field "$dev1" pv_name "$dev1"
 vgcreate $vg "$created"
 # 'no parse errors and VG really exists'