[C++] Some states in swiss join code are useless

[zanmato1984]

Describe the enhancement requested

There exists a member in HashJoinNode identifying wether the hash table is built so we can proceed with probe in a very high level:

arrow/cpp/src/arrow/acero/hash_join_node.cc

Line 1039 in 1e45e18

bool hash_table_ready_ = false;

So the following two states in SwissJoin:

arrow/cpp/src/arrow/acero/swiss_join.cc

Line 2930 in 1e45e18

std::atomic<bool> hash_table_ready_;

arrow/cpp/src/arrow/acero/swiss_join.cc

Line 2913 in 1e45e18

bool hash_table_ready;

are useless. We can also tell it from the fact that they are all written but never read (except for a DCHECK which is also unnecessary).

Component(s)

C++

[zanmato1984]

Issue resolved by pull request 45136
#45136