prevent the primaryGpu is a usb device in multi-gpu scenes

if usb device is the primaryGpu, the device unplug kwin_wayland exit

} else if (device->action() == QStringLiteral("remove")) { DrmGpu *gpu = findGpu(device->devNum()); if (gpu) { if (primaryGpu() == gpu) { qCCritical(KWIN_DRM) << "Primary gpu has been removed! Quitting..."; QCoreApplication::exit(1); return; } else { gpu->setRemoved(); updateOutputs(); } }