block: kill off REQ_UNPLUG

With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

kernel/power/block_io.c

@@ -28,7 +28,7 @@
 static int submit(int rw, struct block_device *bdev, sector_t sector,
 		struct page *page, struct bio **bio_chain)
 {
-	const int bio_rw = rw | REQ_SYNC | REQ_UNPLUG;
+	const int bio_rw = rw | REQ_SYNC;
 	struct bio *bio;
 
 	bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);