Patch: name-finder fd leak fix

[Andrew Haley]

Tom Tromey writes:
 > I think it is possible for name-finder to leak file descriptors.
 > For instance, if the first pipe() succeeds but the second one fails,
 > this will happen.  Or, if the fdopen fails (can this really happen?),
 > then we will leak an fd.
 > 
 > This patch fixes the problem.  Andrew, what do you think?

Fine, although if pipe() fails we're in a bad way already.

Andrew.