fix IntrusiveQueue::remove: several bugs that led to improper state of the queue
fix IntrusiveQueue::remove: several bugs that led to improper state of the queue

We also have to set removeNode->next to null, as it is used to test if the
item is in the queue.

acfloria/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,krbeverx/Firmware,acfloria/Firmware,acfloria/Firmware,PX4/Firmware,krbeverx/Firmware,acfloria/Firmware,krbeverx/Firmware,acfloria/Firmware,krbeverx/Firmware,acfloria/Firmware,acfloria/Firmware