Fix cppcheck warnings

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Ie007785a9afd036e964ba3457fdeb2e6097c9223
diff --git a/main.cpp b/main.cpp
index 2f40341..1927f4e 100644
--- a/main.cpp
+++ b/main.cpp
@@ -10,7 +10,7 @@
     auto bus = sdbusplus::bus::new_default();
     sd_event* event = nullptr;
 
-    auto eventDeleter = [](sd_event* e) { e = sd_event_unref(e); };
+    auto eventDeleter = [](sd_event* e) { sd_event_unref(e); };
     using SdEvent = std::unique_ptr<sd_event, decltype(eventDeleter)>;
 
     // acquire a reference to the default event loop