fix a memory leak in ssl3_generate_key_block fix the error handling in ssl3_change_cipher_state

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2164)
(cherry picked from commit a6fd7c1d)