End connection on destruction

End connection on destruction

End connection on destruction so that each port is disconnected once the
connection is destroyed. Otherwise each port keeps its connection
pointer as is which point to freed memory.

bt_connection_end() already makes sure to finalize each created
notification iterator, so all is left in the destructor is to free the
array of iterators and the connection itself.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>