rm_work: fix build break for do_image_complete

rm_work: fix build break for do_image_complete

* since following commit:
  commit 2ff9d40dc88d43567472218cf3d3faf414398c71
  Author: Richard Purdie <richard.purdie@linuxfoundation.org>
  Date:   Sun Jul 30 16:06:57 2017 +0100

    image/rm_work: Promote do_image_complete to be more sstate like

  all image rm_work tasks are failing with:
  mv: 1.0-r0.do_image_complete.228730130ba309f85b73b72222ba11d7.raspberrypi3 and
      1.0-r0.do_image_complete.228730130ba309f85b73b72222ba11d7.raspberrypi3 are the same file

  it's because for $i 1.0-r0.do_image_complete.228730130ba309f85b73b72222ba11d7.raspberrypi3
  there will be first SSTATETASK in $j do_deploy, so the sed call doesn't replace anything

  It might be different order of SSTATETASKS in my builds (it might work only when
  do_image_complete is the first one in the list), but here:
  SSTATETASKS="do_deploy do_image_complete do_image_qa do_package do_package_qa do_package_write_ipk do_packagedata do_populate_lic do_populate_sdk do_populate_sdk_ext do_populate_sysroot"

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>