Function librdkafka_sys::rd_kafka_produce

pub unsafe extern fn rd_kafka_produce(rkt: *mut rd_kafka_topic_t,
                                      partition: int32_t,
                                      msgflags: c_int,
                                      payload: *mut c_void,
                                      len: size_t,
                                      key: *const c_void,
                                      keylen: size_t,
                                      msg_opaque: *mut c_void)
                                      -> c_int