Fix some warnings by cppcheck

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Icee0abe2e3130aa225db776efdcd47200eb38f8d
diff --git a/fault-monitor/fru-fault-monitor.cpp b/fault-monitor/fru-fault-monitor.cpp
index d59aa16..fb4f891 100644
--- a/fault-monitor/fru-fault-monitor.cpp
+++ b/fault-monitor/fru-fault-monitor.cpp
@@ -78,6 +78,7 @@
         elog<ObjectNotFoundErr>(ObjectNotFoundError::METHOD_NAME("GetObject"),
                                 ObjectNotFoundError::PATH(path.c_str()),
                                 ObjectNotFoundError::INTERFACE(OBJMGR_IFACE));
+        return {};
     }
 
     return mapperResponse.cbegin()->first;