btrfs: get fs_info from trans in btrfs_setup_space_cache

We can read fs_info from the transaction and can drop it from the
parameters.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -2769,8 +2769,7 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
 				   struct btrfs_fs_info *fs_info);
-int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
-			    struct btrfs_fs_info *fs_info);
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 int btrfs_read_block_groups(struct btrfs_fs_info *info);

fs/btrfs/extent-tree.c

@@ -3531,9 +3531,9 @@ static int cache_save_setup(struct btrfs_block_group_cache *block_group,
 	return ret;
 }
 
-int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
-			    struct btrfs_fs_info *fs_info)
+int btrfs_setup_space_cache(struct btrfs_trans_handle *trans)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_block_group_cache *cache, *tmp;
 	struct btrfs_transaction *cur_trans = trans->transaction;
 	struct btrfs_path *path;

fs/btrfs/transaction.c

@@ -1104,7 +1104,7 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans)
 	if (ret)
 		return ret;
 
-	ret = btrfs_setup_space_cache(trans, fs_info);
+	ret = btrfs_setup_space_cache(trans);
 	if (ret)
 		return ret;