pgsql: Remove temporary WAL and history files at the end of archive rec

Remove temporary WAL and history files at the end of archive recovery

cbc55da has reworked the order of some actions at the end of archive
recovery.  Unfortunately this overlooked the fact that the startup
process needs to remove RECOVERYXLOG (for temporary WAL segment newly
recovered from archives) and RECOVERYHISTORY (for temporary history
file) at this step, leaving the files around even after recovery ended.

Backpatch to 9.5, like the previous commit.

Author: Sawada Masahiko
Reviewed-by: Fujii Masao, Michael Paquier
Discussion: https://postgr.es/m/CAD21AoBO_eDQub6zojFnWtnmutRBWvYf7=cW4Hsqj+U_R26w3Q@mail.gmail.com
Backpatch-through: 9.5

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/df86e52cace2c4134db51de6665682fb985f3195

Modified Files
--------------
src/backend/access/transam/xlog.c    | 24 ++++++++++++------------
src/test/recovery/t/002_archiving.pl | 25 ++++++++++++++++++++++++-
2 files changed, 36 insertions(+), 13 deletions(-)