Remove some variables which were set but not used.
gcc (at least as of version 4.6.0) is kind enough to point these out to us,
(when given -Wunused-but-set-variable explicitly or implicitly via -Wunused
or -Wall).
One of these cases was a legitimately unused variable. Two were simply
variables (named ignored) we were assigning only to squelch a warning about
unused function return values. I don't seem to be getting those warnings
even without setting the ignored variable. And the gcc docs. say that the
correct way to squelch that warning is with a cast to (void) anyway.