Revert dup2() checking in syslogger.c

Revert dup2() checking in syslogger.c

Per the expanded comment-

As we're just trying to reset these to go to DEVNULL, there's not
much point in checking for failure from the close/dup2 calls here,
if they fail then presumably the file descriptors are closed and
any writes will go into the bitbucket anyway.

Pointed out by Tom.