daemon: Fix some more error paths in the double forking.
As spotted by Tanu Kaskinen:
The first process: daemon_pipe is not closed if the first fork() call
fails. Even if it doesn't fail, the first process never closes
daemon_pipe[0].
The second process: daemon_pipe[1] is not closed if anything fails
between the first and the second fork() call. Also, if the second fork
fails, then the finish section writes to daemon_pipe2[1], even though
only the third process should do that. Also, if anything fails between
the first and the second fork, then the second process never writes
anything to daemon_pipe[1]. I don't know what happens in the first
process in this case - does it get an error or does pa_loop_read() get
stuck.