openvpnserv: clarify return values type

openvpnserv: clarify return values type

Functions openvpn_vsntprintf and openvpn_sntprintf return
values of type int, but in reality it is always 0 or 1 (and -1 for
snrptinf), which can be represented as boolean.

To make code clearer, change return type to BOOL. Also
use stdbool.h header instead of bool definition macros in automatic.c.

Signed-off-by: Lev Stipakov <lev@openvpn.net>
Acked-by: Selva Nair <selva.nair@gmail.com>
Message-Id: <1538587281-3209-1-git-send-email-lstipakov@gmail.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg17532.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>