btrfs: drop unused space_info parameter from create_space_info

Since commit dc2d3005 ("btrfs: remove dead create_space_info
calls"), there is only one caller btrfs_init_space_info. However, it
doesn't need create_space_info to return space_info at all.
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent-tree.c

@@ -4007,8 +4007,7 @@ static const char *alloc_name(u64 flags)
 	};
 }
 
-static int create_space_info(struct btrfs_fs_info *info, u64 flags,
-			     struct btrfs_space_info **new)
+static int create_space_info(struct btrfs_fs_info *info, u64 flags)
 {
 
 	struct btrfs_space_info *space_info;
@@ -4046,7 +4045,6 @@ static int create_space_info(struct btrfs_fs_info *info, u64 flags,
 		return ret;
 	}
 
-	*new = space_info;
 	list_add_rcu(&space_info->list, &info->space_info);
 	if (flags & BTRFS_BLOCK_GROUP_DATA)
 		info->data_sinfo = space_info;
@@ -10825,7 +10823,6 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
 
 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_space_info *space_info;
 	struct btrfs_super_block *disk_super;
 	u64 features;
 	u64 flags;
@@ -10841,21 +10838,21 @@ int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
 		mixed = 1;
 
 	flags = BTRFS_BLOCK_GROUP_SYSTEM;
-	ret = create_space_info(fs_info, flags, &space_info);
+	ret = create_space_info(fs_info, flags);
 	if (ret)
 		goto out;
 
 	if (mixed) {
 		flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
-		ret = create_space_info(fs_info, flags, &space_info);
+		ret = create_space_info(fs_info, flags);
 	} else {
 		flags = BTRFS_BLOCK_GROUP_METADATA;
-		ret = create_space_info(fs_info, flags, &space_info);
+		ret = create_space_info(fs_info, flags);
 		if (ret)
 			goto out;
 
 		flags = BTRFS_BLOCK_GROUP_DATA;
-		ret = create_space_info(fs_info, flags, &space_info);
+		ret = create_space_info(fs_info, flags);
 	}
 out:
 	return ret;