unix: don't close kqueue fd in kqueue_fork()
unix: don't close kqueue fd in kqueue_fork()

The file descriptor is not inherited by the child process. Trying to close it is
not just useless, it's actively harmful - if the close() call succeeds, it will
have closed an altogether different file descriptor.

unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso,urbit/archaeology2,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,urbit/archaeology2,urbit/archaeology2,urbit/archaeology2,urbit/archaeology2