DeviceSupport: Silence soft assert

Change-Id: Ifa5bcbb799fcfeb25254a87a1e3e62bc8864bf4d
Reviewed-by: hjk <hjk@qt.io>

src/plugins/projectexplorer/devicesupport/idevicefactory.cpp

@@ -67,7 +67,8 @@ IDevice::Ptr IDeviceFactory::create() const
         return {};
 
     IDevice::Ptr device = m_creator();
-    QTC_ASSERT(device, return {});
+    if (!device) // e.g. Cancel used on the dialog to create a device
+        return {};
     device->setDefaultDisplayName(displayName());
     return device;
 }