Btrfs: remove path arg from btrfs_truncate_free_space_cache

Not used for anything, and removing it avoids caller's need to
allocate a path structure.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index b863e45..014de49 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -466,7 +466,7 @@
 	}
 
 	if (i_size_read(inode) > 0) {
-		ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
+		ret = btrfs_truncate_free_space_cache(root, trans, inode);
 		if (ret) {
 			if (ret != -ENOSPC)
 				btrfs_abort_transaction(trans, root, ret);