dsound/tests: Primary and secondary buffers use the same IDirectSoundBuffer vtbl.

dlls/dsound/tests/dsound.c

@@ -627,6 +627,9 @@ static HRESULT test_primary_secondary(LPGUID lpGuid)
                "IDirectSound_CreateSoundBuffer() failed to create a secondary buffer %08x\n",rc);
 
             if (rc==DS_OK && secondary!=NULL) {
+                todo_wine ok(primary->lpVtbl==secondary->lpVtbl,
+                            "Primary and secondary buffers have different vtbls.\n");
+
                 test_buffer(dso,&secondary,0,FALSE,0,FALSE,0,
                             winetest_interactive,1.0,0,NULL,0,0,FALSE,0);
 

dlls/dsound/tests/dsound8.c

@@ -639,6 +639,9 @@ static HRESULT test_primary_secondary8(LPGUID lpGuid)
                "buffer %08x\n",rc);
 
             if (rc==DS_OK && secondary!=NULL) {
+                todo_wine ok(primary->lpVtbl==secondary->lpVtbl,
+                            "Primary and secondary buffers have different vtbls.\n");
+
                 test_buffer8(dso,&secondary,0,FALSE,0,FALSE,0,
                              winetest_interactive,1.0,0,NULL,0,0);