test: controls: control_list: Add status check

Since commit fac471e812 ("test: Extract CameraTest class out of camera
tests to libtest") the control_list is a subclass of CameraTest, and the
status returned by the base class init() operation should be inspected
to avoid accessing uninitialized fields during the run() operation
execution.

If the VIMC test module is not loaded, executing the test results in a
segfault. Fix this by adding the init() operation where to status_ flag
is checked for errors.

Fixes: fac471e812 ("test: Extract CameraTest class out of camera tests to libtest")
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

test/controls/control_list.cpp

@@ -29,7 +29,12 @@ public:
 	}
 
 protected:
-	int run()
+	int init() override
+	{
+		return status_;
+	}
+
+	int run() override
 	{
 		CameraControlValidator validator(camera_.get());
 		ControlList list(controls::controls, &validator);