Use buf_cpy instead of copying buffers byte by byte
* cipher/bufhelp.h (buf_cpy): Skip memcpy if length is zero. * cipher/cipher-ccm.c (do_cbc_mac): Replace buffer copy loops with buf_cpy call. * cipher/cipher-cmac.c (_gcry_cmac_write): Ditto. * cipher/cipher-ocb.c (_gcry_cipher_ocb_authenticate): Ditto.
- Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>