Correct the return value of BIO_get_ktls_*().

Correct the return value of BIO_get_ktls_*().

BIO_get_ktls_send() and BIO_get_ktls_recv() are documented as
returning either 0 or 1.  However, they were actually returning the
internal value of the associated BIO flag for the true case instead of
1.

Also trim redundant ternary operators.

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14023)