nvmet-fc: free queue and assoc directly

Neither struct nvmet_fc_tgt_queue nor struct nvmet_fc_tgt_assoc are data
structure which are used in a RCU context. So there is no reason to
delay the free operation.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>