'what' doesn't use perror to print open errors, Sys V/3.0

[Guy Harris]

>According to the manual pages for Microport V/386 3.0e, fopen returns
>an error status in errno and perror is defined to work for system
>calls and library functions.
>
>I don't have the manual pages for other systems handy, but I seem to
>recall similar wording for BSD and SunOS.

No, I checked the 4.3-tahoe and SunOS 4.0 "fopen" man pages; they
mention "errno" nowhere.