Windows: fix memleaks

src/detection/host/host_windows.cpp

@@ -28,5 +28,5 @@ extern "C" void ffDetectHostImpl(FFHostResult* host)
         record.getString(L"Vendor", &host->sysVendor);
     }
     else
-        ffStrbufInitS(&host->error, "No Wmi result returned");
+        ffStrbufAppendS(&host->error, "No Wmi result returned");
 }

src/util/windows/wmi.cpp

@@ -128,7 +128,7 @@ FFWmiQuery::FFWmiQuery(const wchar_t* queryStr, FFstrbuf* error)
     if (InitOnceExecuteOnce(&s_InitOnce, &InitHandleFunction, nullptr, (void**)&context) == FALSE)
     {
         if(error)
-            ffStrbufInitS(error, context);
+            ffStrbufAppendS(error, context);
         return;
     }