patch: Make sort-test handle more then 100 lines, and avoid segfault

[Roland McGrath]

> Sure.  The casting is needed to avoid a compile warning.  

The correct fix for that is to remove `const' from the types in the struct.

> Is this version better?  

There should be a space after the cast as well (when there is a cast that
should stay).

> The usage message became a bit strange, but I ignore it as this is a
> internal test program for glibc.

Not a problem.


Thanks,
Roland