frontend: Use static_cast when casting from void pointers

Using static_cast is preferred here, as it is safer to use than
reinterpret_cast.

frontend/widgets/OBSBasic_VolControl.cpp

@@ -99,7 +99,7 @@ void OBSBasic::UnhideAllAudioControls()
 
 	auto PreEnum = [](void *data, obs_source_t *source) -> bool /* -- */
 	{
-		return (*reinterpret_cast<UnhideAudioMixer_t *>(data))(source);
+		return (*static_cast<UnhideAudioMixer_t *>(data))(source);
 	};
 
 	obs_enum_sources(PreEnum, &UnhideAudioMixer);