There's no point in failing if DISPLAY isn't set if we don't
boot a qemu image when using a controller like SimpleRemoteTarget
or GummibootTarget.
(From OE-Core rev: 9fcd3af8626e1b0979b0cde745fe0880ccc50de7)
Signed-off-by: Stefan Stanacar <stefanx.stanacar@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>