decklink: Fix crash during shutdown when output is on

The actual crash is caused because obs_module_unload() is called before
the decklink outputs are stopped. In obs_module_unload(), the deviceEnum
pointer is freed. During decklink_output_stop(), the removed code tries
to retrieve a reference of the decklink device from the deviceEnum and
crashes because it has already been freed. This code appears to serve no
purpose anyway, so we remove it.

plugins/decklink/decklink-output.cpp

@@ -104,10 +104,6 @@ static void decklink_output_stop(void *data, uint64_t)
 
 	obs_output_end_data_capture(decklink->GetOutput());
 
-	ComPtr<DeckLinkDevice> device;
-
-	device.Set(deviceEnum->FindByHash(decklink->deviceHash));
-
 	decklink->Deactivate();
 }