btrfs: clear dirty status from extent buffer on error at insert_new_root()

btrfs: clear dirty status from extent buffer on error at insert_new_root()

If we failed to insert the tree mod log operation, we are not removing the
dirty status from the allocated and dirtied extent buffer before we free
it. Removing the dirty status is needed for several reasons such as to
adjust the fs_info->dirty_metadata_bytes counter and remove the dirty
status from the respective folios. So add the missing call to
btrfs_clear_buffer_dirty().

Fixes: f61aa7ba08ab ("btrfs: do not BUG_ON() on tree mod log failure at insert_new_root()")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>