Since commit 70200574 ("block: remove QUEUE_FLAG_DISCARD"),
blk_queue_flag_test_and_set() has not been used, so delete it.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240627160735.842189-1-john.g.garry@oracle.comSigned-off-by: Jens Axboe <axboe@kernel.dk>