[Bug-apl] ⎕FIO[1] behavior

[David B. Lamkins]

I think that the behavior of ⎕fio[1] changed at some point. This is supposed to 
return the value of errno (a positive value), but now returns -errno, causing 
⎕fio[2] ⎕fio[1] ⍬ to always return "Unknown error ...".