btrfs use bio_list_merge_init

Use bio_list_merge_init instead of open coding bio_list_merge and
bio_list_init.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240328084147.2954434-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Christoph Hellwig

fs/btrfs/raid56.c

@@ -331,12 +331,11 @@ static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
 static void merge_rbio(struct btrfs_raid_bio *dest,
 		       struct btrfs_raid_bio *victim)
 {
-	bio_list_merge(&dest->bio_list, &victim->bio_list);
+	bio_list_merge_init(&dest->bio_list, &victim->bio_list);
 	dest->bio_list_bytes += victim->bio_list_bytes;
 	/* Also inherit the bitmaps from @victim. */
 	bitmap_or(&dest->dbitmap, &victim->dbitmap, &dest->dbitmap,
 		  dest->stripe_nsectors);
-	bio_list_init(&victim->bio_list);
 }
 
 /*