pgsql: Fix pg_stat_get_backend_activity() to use multi-byte truncated r

Fix pg_stat_get_backend_activity() to use multi-byte truncated result

pg_stat_get_backend_activity() calls pgstat_clip_activity() to ensure
that the reported query string is correctly truncated when it finishes
with an incomplete multi-byte sequence. However, the result returned by
the function was not what pgstat_clip_activity() generated, but the
non-truncated, original, contents from PgBackendStatus.st_activity_raw.

Oversight in 54b6cd589ac2, so backpatch all the way down.

Author: Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com>
Discussion: https://postgr.es/m/CAEoWx2mDzwc48q2EK9tSXS6iJMJ35wvxNQnHX+rXjy5VgLvJQw@mail.gmail.com
Backpatch-through: 14

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/36b8f4974a884a7206df97f37ea62d2adc0b77f0

Modified Files
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src/backend/utils/adt/pgstatfuncs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)