* qemud/qemud.c (remoteReadConfigFile): Don't return 0 (success)
when the config file is unreadable or nonexistent
Return -1, not 0, upon virConfReadFile failure.
(main): If remote_config_file is not specified via --config(-f),
use the default config file only if it exists. Otherwise,
use /dev/null.
* src/conf.c (virConfReadFile): Don't diagnose virFileReadAll
failure, since it already does that.