block: Don't implicitly trigger event check on disk_unblock_events()

Currently, disk_unblock_events() implicitly kick event check if the
block count reaches zero.  This behavior is not described in the
comment and hinders with future changes.  Make the unblocker
explicitly check events by calling disk_check_events() as necessary.

This patch doesn't cause any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kay Sievers <kay.sievers@vrfy.org>

block/genhd.c

@@ -1494,7 +1494,7 @@ void disk_block_events(struct gendisk *disk)
 void disk_unblock_events(struct gendisk *disk)
 {
 	if (disk->ev)
-		__disk_unblock_events(disk, true);
+		__disk_unblock_events(disk, false);
 }
 
 /**

fs/block_dev.c

@@ -1446,6 +1446,7 @@ int blkdev_put(struct block_device *bdev, fmode_t mode)
 		if (bdev_free) {
 			if (bdev->bd_write_holder) {
 				disk_unblock_events(bdev->bd_disk);
+				disk_check_events(bdev->bd_disk);
 				bdev->bd_write_holder = false;
 			} else
 				disk_check_events(bdev->bd_disk);