btrfs: get fs_info from trans in btrfs_write_dirty_block_groups

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

@@ -2767,8 +2767,7 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 			 u64 root_objectid, u64 owner, u64 offset);
 
 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_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 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);

fs/btrfs/extent-tree.c

@@ -3736,9 +3736,9 @@ int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans)
 	return ret;
 }
 
-int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
-				   struct btrfs_fs_info *fs_info)
+int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans)
 {
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_block_group_cache *cache;
 	struct btrfs_transaction *cur_trans = trans->transaction;
 	int ret = 0;

fs/btrfs/transaction.c

@@ -1132,7 +1132,7 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans)
 	}
 
 	while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) {
-		ret = btrfs_write_dirty_block_groups(trans, fs_info);
+		ret = btrfs_write_dirty_block_groups(trans);
 		if (ret)
 			return ret;
 		ret = btrfs_run_delayed_refs(trans, (unsigned long)-1);