OpenSSL: fix a debug format string.
OpenSSL: fix a debug format string.

There are four parameters after this format string, but the string only
contains three placeholders. GCC, quite rightly, gets upset.  This was
broken in 551e3ad.

Reviewed-by: Jonny Lamb <3d1fb3642aaab2ff70e3392a5ab916bf99eed6a3@collabora.co.uk>

freedesktop-unofficial-mirror/wocky,noonien-d/wocky,noonien-d/wocky,freedesktop-unofficial-mirror/wocky,noonien-d/wocky,freedesktop-unofficial-mirror/wocky