fix for more minor memory leaks

fix for more minor memory leaks

Now that some pointers have lost their const attribute, we can free their
associated memory when done with them.  This is more a correctness issue
about the rule for freeing those pointers which isn't completely trivial
more than the leak itself which didn't matter as the program is
exiting anyway.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>