Fix daemonization
Fix daemonization

Close all inherited fds, not just mark them to-be-closed in spawned process.
Regression by 67a5484b41709f955b1694470f2b79c057a1898e (when this code
was executed inside library, exec(daemon) implictly closed all marked fds; in
daemon, fds should be explicitly closed).

lxde/menu-cache,lxde/menu-cache