block: consistently use GFP_NOIO instead of __GFP_NORECLAIM

Same numerical value (for now at least), but a much better documentation
of intent.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
8 files changed