[libvirt] [PATCH] storage: fix disregarding specified owner/group permissions

Hi, storage_conf.c always sets owner/group permissions as 0, even if non-0 values are specified in XML. Because XPaths in DefParsePerms functions are wrong and XPath functions using the XPaths fail, as a result the values obtained by getpid()/getgid() are used instead. This patch fixes this and also unifies duplicated functions, virStoragePoolDefParsePerms and virStorageVolDefParsePerms, as a common function virStorageDefParsePerms to fix the bug prettily. One concern I have is the default value of mode permission in virStorageDefParsePerms is now 0700 but that in virStorageVolDefParsePerms was 0600. Is this considerable change? Thanks, ozaki-r