Correct `expect_payment_forwarded` upstream channel checking

Correct `expect_payment_forwarded` upstream channel checking

`expect_payment_forwarded` takes a bool to indicate that the
inbound channel on which we received a forwarded payment has been
closed, but then ignores it in favor of looking at the fee in the
event. While this is generally correct, in cases where we process
an event after a channel was closed, which was generated before a
channel closed this is incorrect.

Instead, we examine the bool we already passed and use that.