block: fix kernel-doc format for blkdev_issue_zeroout

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

block/blk-lib.c

@@ -132,7 +132,7 @@ static void bio_batch_end_io(struct bio *bio, int err)
 }
 
 /**
- * blkdev_issue_zeroout generate number of zero filed write bios
+ * blkdev_issue_zeroout - generate number of zero filed write bios
  * @bdev:	blockdev to issue
  * @sector:	start sector
  * @nr_sects:	number of sectors to write