FROMLIST: binder: guarantee txn complete / errors delivered in-order

(from https://patchwork.kernel.org/patch/9817805/

)

Since errors are tracked in the return_error/return_error2
fields of the binder_thread object and BR_TRANSACTION_COMPLETEs
can be tracked either in those fields or via the thread todo
work list, it is possible for errors to be reported ahead
of the associated txn complete.

Use the thread todo work list for errors to guarantee
order. Also changed binder_send_failed_reply to pop
the transaction even if it failed to send a reply.

Change-Id: Ibf93b412b6236812d415bc10fec8b43826948eaa
Signed-off-by: Todd Kjos <tkjos@google.com>