block: remove __blk_put_request()

Now there's no difference between blk_put_request() and
__blk_put_request() anymore, get rid of the underscore version and
convert the few callers.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/scsi/osd/osd_initiator.c

@@ -506,11 +506,11 @@ static void osd_request_async_done(struct request *req, blk_status_t error)
 
 	_set_error_resid(or, req, error);
 	if (req->next_rq) {
-		__blk_put_request(req->q, req->next_rq);
+		blk_put_request(req->next_rq);
 		req->next_rq = NULL;
 	}
 
-	__blk_put_request(req->q, req);
+	blk_put_request(req);
 	or->request = NULL;
 	or->in.req = NULL;
 	or->out.req = NULL;