Fix subscriber's chunk leak in shm_monitor when unknown chunk type is retrieved from iceoryx

[ksuszka]

This MR fixes a memory leak in shm_monitor in release/0.10.4 in the receive_data_wakeup_handler function.

Typical flow in this function is:

• retrieve chunk from iceoryx link
• wrap this chunk into ddsi_serdata structure link
• prepare it for processing
• release reference to ddsi_serdata structure so chunk will be released from iceoryx when ddsi_serdata wrapper won't be needed link

However in some cases if chunk type is not recognized it is not wrapped into ddsi_serdata strcture and currently it is never released. This MR fixes this execution path.

This seems to fix ros2/rmw_cyclonedds#471 for me.

[ksuszka]

I've just noticed it was already fixed on master in f4ea4fc 2 years ago, however it was not back-ported to release 0.10.x which is currently in use in ROS2 Humble.

Could you make a backport of this fix to release 0.10.x so it is fixed in the next update of ROS Humble?

[eboasson]

LGTM, and I agree this is a fix that needs to be easily available for Humble. Thanks!