binderfs: port tests to test harness infrastructure

Makes for nicer output and prepares for additional tests.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200313152420.138777-1-christian.brauner@ubuntu.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>