Round block cipher buffer sizes to multiple of block size
Round block cipher buffer sizes to multiple of block size

Previously --buf-size was taken as a multiple of the block size,
ie --buf-size=5 tested over 5 blocks (rather than 5 bytes, as the
output claimed.)

randombit/botan,Rohde-Schwarz-Cybersecurity/botan,webmaster128/botan,webmaster128/botan,webmaster128/botan,webmaster128/botan,webmaster128/botan,Rohde-Schwarz-Cybersecurity/botan,randombit/botan,Rohde-Schwarz-Cybersecurity/botan,Rohde-Schwarz-Cybersecurity/botan,randombit/botan,Rohde-Schwarz-Cybersecurity/botan,randombit/botan,Rohde-Schwarz-Cybersecurity/botan,randombit/botan