Give everything prototypes (well, everything that's actually used).

ssl/s23_lib.c

diff --git a/ssl/s23_lib.c b/ssl/s23_lib.c
index 8d7dbcf..bcfda91 100644
--- a/ssl/s23_lib.c
+++ b/ssl/s23_lib.c
@@ -93,7 +93,7 @@
 	ssl_bad_method,
 	ssl23_default_timeout,
 	&ssl3_undef_enc_method,
-	ssl_undefined_function,
+	ssl_undefined_void_function,
 	ssl3_callback_ctrl,
 	ssl3_ctx_callback_ctrl,
 	};