CT: fix documentation

 #include <openssl/ssl.h>

 int SSL_ct_enable(SSL *s, int validation_mode);

 int SSL_CTX_ct_enable(SSL_CTX *ctx, int validation_mode);

 int SSL_enable_ct(SSL *s, int validation_mode);

 int SSL_CTX_enable_ct(SSL_CTX *ctx, int validation_mode);

 int SSL_set_ct_validation_callback(SSL *s, ssl_ct_validation_cb callback,

                                    void *arg);

 int SSL_CTX_set_ct_validation_callback(SSL_CTX *ctx,

                                        ssl_ct_validation_cb callback,

                                        void *arg);

 void SSL_ct_disable(SSL *s);

 void SSL_CTX_ct_disable(SSL_CTX *ctx);

 void SSL_disable_ct(SSL *s);

 void SSL_CTX_disable_ct(SSL_CTX *ctx);

 int SSL_ct_is_enabled(const SSL *s);

 int SSL_CTX_ct_is_enabled(const SSL_CTX *ctx);

=head1 DESCRIPTION

SSL_ct_enable() and SSL_CTX_ct_enable() enable the processing of signed

SSL_enable_ct() and SSL_CTX_enable_ct() enable the processing of signed

certificate timestamps (SCTs) either for a given SSL connection or for all

connections that share the given SSL context, respectively.

This is accomplished by setting a built-in CT validation callback.

nor to have specified server verification via DANE-TA(2) or DANE-EE(3) TLSA

records.

SSL_ct_disable() and SSL_CTX_ct_disable() turn off CT processing, whether

SSL_disable_ct() and SSL_CTX_disable_ct() turn off CT processing, whether

enabled via the built-in or the custom callbacks, by setting a NULL callback.

These may be implemented as macros.

SSL_ct_is_enabled() and SSL_CTX_ct_is_enabled() return 1 if CT processing is

enabled via either SSL_ct_enable() or a non-null custom callback, and 0

enabled via either SSL_enable_ct() or a non-null custom callback, and 0

otherwise.

=head1 NOTES

=head1 RETURN VALUES

SSL_ct_enable(), SSL_CTX_ct_enable(), SSL_CTX_set_ct_validation_callback() and

SSL_enable_ct(), SSL_CTX_enable_ct(), SSL_CTX_set_ct_validation_callback() and

SSL_set_ct_validation_callback() return 1 if the B<callback> is successfully

set.

They return 0 if an error occurs, e.g. a custom client extension handler has

been setup to handle SCTs.

SSL_ct_disable() and SSL_CTX_ct_disable() do not return a result.

SSL_disable_ct() and SSL_CTX_disable_ct() do not return a result.

SSL_CTX_ct_is_enabled() and SSL_ct_is_enabled() return a 1 if a non-null CT

validation callback is set, or 0 if no callback (or equivalently a NULL