CameraManager: Ensure we cleanup on failure

If the CameraManager fails to initialise at startup during
CameraManager::Private::init(), then the run() function will prepare the
thread for operations, but the thread will immediately close without
executing any cleanup.

This can leave instantiated objects such as the EventNotifier registered
by the udev enumerator constructed in a thread which no longer exists.
The destructor of those objects can then fire an assertion that they are
being executed from an incorrect thread while performing their cleanup.

Ensure that the failure path does not result in reporting thread
ownership assertions by performing cleanup correctly on the
CameraManager thread before it closes.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/camera_manager.cpp

@@ -80,8 +80,10 @@ void CameraManager::Private::run()
 	mutex_.unlock();
 	cv_.notify_one();
 
-	if (ret < 0)
+	if (ret < 0) {
+		cleanup();
 		return;
+	}
 
 	/* Now start processing events and messages. */
 	exec();