unused return values causing build failures in HEAD

[Julian Graham]

Hey everyone,

So I'm trying to build Guile from HEAD after a hard drive wipe, and it
looks like the version of gcc that ships with Ubuntu 8.10, 4.3.2, now
warns when you don't check function return values, which of course
breaks Guile's warnings-as-errors build.  There are several offending
instances of this, and the functions they use are write, read, pipe,
and nice.  I'm happy to submit a patch that raises SCM_SYSERROR or
whatever in the appropriate places -- unless there's some other way
around this.


Regards,
Julian