tests: fw_cfg: add a function to get the fw_cfg file

This is useful to write qtest about fw_cfg file entry.

Signed-off-by: Li Qiang <liq3ea@163.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190424140643.62457-3-liq3ea@163.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2 files changed