block: remove support for bio remapping from ->make_request

There is very little benefit in allowing to let a ->make_request
instance update the bios device and sector and loop around it in
__generic_make_request when we can archive the same through calling
generic_make_request from the driver and letting the loop in
generic_make_request handle it.

Note that various drivers got the return value from ->make_request and
returned non-zero values for errors.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 32323f0..97f2a5f 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -785,7 +785,7 @@
 	PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
 }
 
-static int make_request(mddev_t *mddev, struct bio * bio)
+static void make_request(mddev_t *mddev, struct bio * bio)
 {
 	conf_t *conf = mddev->private;
 	mirror_info_t *mirror;
@@ -870,7 +870,7 @@
 		if (rdisk < 0) {
 			/* couldn't find anywhere to read from */
 			raid_end_bio_io(r1_bio);
-			return 0;
+			return;
 		}
 		mirror = conf->mirrors + rdisk;
 
@@ -928,7 +928,7 @@
 			goto read_again;
 		} else
 			generic_make_request(read_bio);
-		return 0;
+		return;
 	}
 
 	/*
@@ -1119,8 +1119,6 @@
 
 	if (do_sync || !bitmap || !plugged)
 		md_wakeup_thread(mddev->thread);
-
-	return 0;
 }
 
 static void status(struct seq_file *seq, mddev_t *mddev)