Fix mismatch of fprintf format specifier and argument type

Fix mismatch of fprintf format specifier and argument type

This fixes a warning about a mismatch between a fprintf format string
and an argument type on Darwin-64-bit builds:

%lu specifies type 'unsigned long' but the argument has type
'__darwin_suseconds_t' (aka 'int')

Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <CAEsd45SoC+h5tcDraZcQN_MUYzqWYOVvNpkwMo190DLpB32StQ@mail.gmail.com>
URL: http://article.gmane.org/gmane.network.openvpn.devel/9446

Signed-off-by: Gert Doering <gert@greenie.muc.de>