fuzz: Log output even if fuzzer failed

Summary:
Backport of core PR16236.

The second commit:
https://github.com/bitcoin/bitcoin/pull/16236/commits/fa410f67aa1d0ccd306dc16e438c1a034b8cc049
is not needed because we already have the exception in our suppression
list.

Test Plan:

ninja bitcoin-fuzzer
./test/fuzz/test_runner.py <path_to_corpus>

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D8138