Remove trailing whitespace in comments
astyle was only run on .cpp files this time - already in ff6b66917 where the style cleanup was done initially, not all .h files seem to have gotten the same styling (rerunning astyle on .h files at that commit produces a huge diff).
ff6b66917
The astyle cleanup keeps trailing whitespace within comments, but the whitespace here is not significant nor intentional and thus should be removed.
