Force an EAX2 call to "initialize" EAX with 2.0 paramaeters

This feels like an unnecessarily gross hack, but currently OpenAL Soft
initializes effects differently depending on what property version is used on
the first EAX call with the device (in part because EAX2 and EAX3/4/5 have
different default reverb values, with 2 being silent and 3/4/5 not, yet reverb
is silent by default in DSound).

dsound8.c

@@ -342,12 +342,14 @@ static HRESULT DSShare_Create(REFIID guid, DeviceShare **out)
     }
     if(share->sources.maxhw_alloc > 0 && HAS_EXTENSION(share, EXT_EAX))
     {
+        EAXSet(&DSPROPSETID_EAX20_BufferProperties, DSPROPERTY_EAX20BUFFER_COMMITDEFERREDSETTINGS,
+            share->sources.ids[0], NULL, 0);
         EAXGet(&EAXPROPERTYID_EAX40_Source, EAXSOURCE_ALLPARAMETERS, share->sources.ids[0],
             &share->default_srcprops, sizeof(share->default_srcprops));
         EAXGet(&EAXPROPERTYID_EAX40_Source, EAXSOURCE_ALLSENDPARAMETERS, share->sources.ids[0],
             &share->default_srcsend, sizeof(share->default_srcsend));
-        EAXGet(&EAXPROPERTYID_EAX40_Source, EAXSOURCE_ACTIVEFXSLOTID, share->sources.ids[0],
-            &share->default_srcslots, sizeof(share->default_srcslots));
+        share->default_srcslots[0] = GUID_NULL;
+        share->default_srcslots[1] = EAXPROPERTYID_EAX40_FXSlot0;
     }
     popALContext();