The block size for aes counter mode was improperly set to AES_BLOCK_SIZE.
This sets it to 1 as it is a stream cipher.

This problem was found with by the new extra run-time crypto self test.
Reviewed-by: Conor Mcloughlin <conor.mcloughlin@intel.com>
Tested-by: Sergey Portnoy <sergey.portnoy@intel.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>