Fix cppcheck warnings

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Ie007785a9afd036e964ba3457fdeb2e6097c9223
diff --git a/bmc_epoch.cpp b/bmc_epoch.cpp
index 5889ed3..92f31d8 100644
--- a/bmc_epoch.cpp
+++ b/bmc_epoch.cpp
@@ -27,7 +27,7 @@
 using namespace phosphor::logging;
 
 BmcEpoch::BmcEpoch(sdbusplus::bus::bus& bus, const char* objPath) :
-    EpochBase(bus, objPath), bus(bus)
+    EpochBase(bus, objPath)
 {
     initialize();
 }