a tiny bug

[David Chase]

For Vax 4.2 BSD

The documentation for brk and sbrk does not tell where "caddr_t" is
defined (i.e, what files should I include to get this definition?)

I know that this is a nit, but if nobody complains, it won't get fixed.  I
know this information is easy to find, but it isn't in the documentation
where it belongs.  Expect more nits in the future.  I've had enough.

By the way, it's in sys/types.h.

David Chase, Rice U.