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>
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 874607b..093fb54 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -432,8 +432,8 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 	struct bio *bio;
 
 	/*
-	 * bio_alloc() is guaranteed to return a bio when called with
-	 * __GFP_RECLAIM and we request a valid number of vectors.
+	 * bio_alloc() is guaranteed to return a bio when allowed to sleep and
+	 * we request a valid number of vectors.
 	 */
 	bio = bio_alloc(GFP_KERNEL, nr_vecs);