btrfs emtpy partition creation is currently not working because of the
usage of the non existant variables rootfs ans extra_imagecmd. It also
as an incorrect size.
Change-Id: I7cb0b669cca8caa061aa292d9d355a3c21767bc9 Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
