pgsql: Remove unneeded field from VACUUM state.

Remove unneeded field from VACUUM state.

Bugfix commit 5fc89376 effectively made the lock_waiter_detected field
from vacuumlazy.c's global state struct into private state owned by
lazy_truncate_heap().  Finish this off by replacing the struct field
with a local variable.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/958cfbcf2dd338e3179c2d8a35f48bde020eba60

Modified Files
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src/backend/access/heap/vacuumlazy.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)