The docs are in the wrong location: /usr/share/doc/postfix-1.1.0/ It looks like the subpackage for pflogsumm is resetting the %{version} macro to pflogsumm's version (1.1.0) instead of postfix' version (2.0.19, now), which in turn horks %{postfix_doc_dir} and everything that cascades off of it...
Should be fixed in 2.0.18-4 (which is still building), good catch, I didn't notice the doc directory got reset (John, who wishes rpm was a real language with scope, hierarchy, correct parsing, etc. so he doesn't get burned over expectations over how rpm will work :-) :-) I am aware postfix is now up to 2.0.19, at the time I did the last update the TLS and IPV6 patches weren't out for 2.0.19 yet. I will upgrade to 2.0.19 soon.