s/VIR_ERR_NO_SUPPORT/VIR_ERR_OPERATION_INVALID/

Special case is changes on lxcDomainInterfaceStats, if it's not
implemented on the platform, prints error like:

    lxcError(VIR_ERR_OPERATION_INVALID, "%s",
             _("interface stats not implemented on this platform"));

As the function is supported by driver actually, error like
VIR_ERR_NO_SUPPORT is confused.