btrfs: get fs_info from eb in btrfs_leaf_free_space

We can read fs_info from extent buffer and can drop it from the
parameters.

Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/file.c

@@ -1050,7 +1050,7 @@ delete_extent_item:
 	if (!ret && replace_extent && leafs_visited == 1 &&
 	    (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
 	     path->locks[0] == BTRFS_WRITE_LOCK) &&
-	    btrfs_leaf_free_space(fs_info, leaf) >=
+	    btrfs_leaf_free_space(leaf) >=
 	    sizeof(struct btrfs_item) + extent_item_size) {
 
 		key.objectid = ino;