[PATCH 4/5] fix wrong printf formatting of signed/unsigned integers

[Daniel Kahn Gillmor]

this series up to patch 4 LGTM, and seem uncontroversial.  patch 5 adds
FIXMEs that should probably actually be fixed, though, rather than just
flagged.

Thanks to Piotr for identifying these issues and suggesting the
cleanup.

         --dkg