btrfs: get fs_info from block group in load_free_space_cache

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

fs/btrfs/extent-tree.c

@@ -643,7 +643,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
 
 	if (btrfs_test_opt(fs_info, SPACE_CACHE)) {
 		mutex_lock(&caching_ctl->mutex);
-		ret = load_free_space_cache(fs_info, cache);
+		ret = load_free_space_cache(cache);
 
 		spin_lock(&cache->lock);
 		if (ret == 1) {

fs/btrfs/free-space-cache.c

@@ -812,9 +812,9 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
 	goto out;
 }
 
-int load_free_space_cache(struct btrfs_fs_info *fs_info,
-			  struct btrfs_block_group_cache *block_group)
+int load_free_space_cache(struct btrfs_block_group_cache *block_group)
 {
+	struct btrfs_fs_info *fs_info = block_group->fs_info;
 	struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
 	struct inode *inode;
 	struct btrfs_path *path;

fs/btrfs/free-space-cache.h

@@ -50,8 +50,7 @@ int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
 				    struct btrfs_block_group_cache *block_group,
 				    struct inode *inode);
-int load_free_space_cache(struct btrfs_fs_info *fs_info,
-			  struct btrfs_block_group_cache *block_group);
+int load_free_space_cache(struct btrfs_block_group_cache *block_group);
 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
 			struct btrfs_block_group_cache *block_group,
 			struct btrfs_path *path);