Bluetooth: hidp: test "terminate" before sleeping

The "terminate" flag is guaranteed to be set before the session terminates
and the handlers are woken up. Hence, we need to add it to the
sleep-condition.

Note that testing the flags is not enough as nothing prevents us from
setting the flags again after the session-handler terminated.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>