app: update the method name

update watchdog names to use `Lower Camel Case`.

Change-Id: I654ddb1a37330f946f258c471fc4209e71cf4d82
Signed-off-by: George Liu <liuxiwei@ieisystem.com>
diff --git a/app/watchdog_service.hpp b/app/watchdog_service.hpp
index 5717066..86c31da 100644
--- a/app/watchdog_service.hpp
+++ b/app/watchdog_service.hpp
@@ -102,7 +102,7 @@
     /** @brief sdbusplus handle */
     sdbusplus::bus_t bus;
     /** @brief The name of the mapped host watchdog service */
-    static ipmi::ServiceCache wd_service;
+    static ipmi::ServiceCache wdService;
 
     /** @brief Gets the value of the property on the host watchdog
      *