nvmet-fcloop: call done callback even when remote port is gone

When the target port is gone, it's not possible to access any of the
request resources. The function should just silently drop the response.
The comment is misleading in this regard.

Though it's still necessary to call the driver via the ->done callback
so the driver is able to release all resources.

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/all/CAHj4cs-OBA0WMt5f7R0dz+rR4HcEz19YLhnyGsj-MRV3jWDsPg@mail.gmail.com/


Fixes: 84eedced ("nvmet-fcloop: drop response if targetport is gone")
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>