Close the given channel.
See vortex_channel_close_full for more details. This function works the same as the previous one, but without providing a user defined pointer that is passed to the optional handler provided.
|channel ||the channel to free |
|on_closed ||a optional handler notification|
- axl_true if the channel was closed or axl_false if not. On threaded mode, activated by defining the on_closed handler, always return axl_true. Actual close process result is notified on on_closed