Improve heartbeats coding style
Improve heartbeats coding style

Based on an orignal commit by GitHub user BertramScharpf. Rebased and
updated to take account of all the updates since this was first raised.

GH PR#62

Reviewed-by: Rich Salz <c04971a99e5a9ee80eaab4b1deb37e845b0bd697@openssl.org>

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl