btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root

We are now using these for all roots, rename them to btrfs_put_root()
and btrfs_grab_root();

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 66170c8c..6329818 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -580,7 +580,7 @@ void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 	while (!list_empty(&splice) && nr) {
 		root = list_first_entry(&splice, struct btrfs_root,
 					ordered_root);
-		root = btrfs_grab_fs_root(root);
+		root = btrfs_grab_root(root);
 		BUG_ON(!root);
 		list_move_tail(&root->ordered_root,
 			       &fs_info->ordered_roots);
@@ -588,7 +588,7 @@ void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 
 		done = btrfs_wait_ordered_extents(root, nr,
 						  range_start, range_len);
-		btrfs_put_fs_root(root);
+		btrfs_put_root(root);
 
 		spin_lock(&fs_info->ordered_root_lock);
 		if (nr != U64_MAX) {