Merge #11866: Do not un-mark fInMempool on wallet txn if ATMP fails.

Summary:
6ef86c9 Do not un-mark fInMempool on wallet txn if ATMP fails. (Matt Corallo)

Pull request description:

Irrespective of the failure reason, un-marking fInMempool
out-of-order is incorrect - it should be unmarked when
TransactionRemovedFromMempool fires.

Clean up of #11839, which I think was the wrong fix.

Tree-SHA512: 580731297eeac4c4c99ec695e15b09febf62249237bc367fcd1830fc811d3166f9336e7aba7f2f6f8601960984ae22cebed781200db0f04e7cd2008db1a83f64

Backport of Core PR11866
https://github.com/bitcoin/bitcoin/pull/11866/

Test Plan:

make check

Reviewers: deadalnix, Fabien, jasonbcox, O1 Bitcoin ABC, #bitcoin_abc, markblundeberg

Reviewed By: Fabien, O1 Bitcoin ABC, #bitcoin_abc, markblundeberg

Differential Revision: https://reviews.bitcoinabc.org/D4733