pgsql: Move check for fsync=off so that pendingOps still gets cleared.

Move check for fsync=off so that pendingOps still gets cleared.

Commit 3eb77eba5a moved the loop and refactored it, and inadvertently
changed the effect of fsync=off so that it also skipped removing entries
from the pendingOps table. That was not intentional, and leads to an
assertion failure if you turn fsync on while the server is running and
reload the config.

Backpatch-through: 12-
Reviewed-By: Thomas Munro
Discussion: https://www.postgresql.org/message-id/3cbc7f4b-a5fa-56e9-9591-c886deb07513%40iki.fi

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/891a2007e3987545a2543c1f04cd0682576b39fa

Modified Files
--------------
src/backend/storage/sync/sync.c | 148 ++++++++++++++++++++--------------------
1 file changed, 75 insertions(+), 73 deletions(-)