[9fans] bugs in test command

[lawler . jack]

I updated my system today and had trouble with
the usbfat:, 9fat:, and pull scripts because of errors
by the new test command.

        term% ls /dev/kfs.cmd
        ls: /dev/kfs.cmd: '/dev/kfs.cmd' file does not exist
        term% test -f /dev/kfs.cmd
        term% echo $status
        
        term%


Thank you.