block: rename GENHD_FL_NO_PART_SCAN to GENHD_FL_NO_PART

The GENHD_FL_NO_PART_SCAN controls more than just partitions canning,
so rename it to GENHD_FL_NO_PART.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20211122130625.1136848-7-hch@lst.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>