block: Remove an obsolete comment from sg_io()

Commit b7819b9259 ("block: remove the blk_execute_rq return value")
changed the return type of blk_execute_rq() from int into void. That
change made a comment in sg_io() obsolete. Hence remove that comment.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20210413034142.23460-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/scsi_ioctl.c

@@ -353,10 +353,6 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 
 	start_time = jiffies;
 
-	/* ignore return value. All information is passed back to caller
-	 * (if he doesn't check that is his problem).
-	 * N.B. a non-zero SCSI status is _not_ necessarily an error.
-	 */
 	blk_execute_rq(bd_disk, rq, at_head);
 
 	hdr->duration = jiffies_to_msecs(jiffies - start_time);