phosphor-watchdog: Cleanup CodeChecker Errors

Removed the following error messages:
bugprone-unused-raii
  - object destroyed immediately after creation; did you mean to name
  the object
performance-move-const-arg
  - std::move of the variable 'maybeFallback' of the trivially-copyable
  type 'std::optional' has no effect; remove std::move()
clang-diagnostic-inconsistent-missing-override
  - 'interval' overrides a member function but is not marked 'override'

Change-Id: I0f6ab3002b7175a73449d58ea6ae6b66f7c851ef
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/src/watchdog.hpp b/src/watchdog.hpp
index 736e71f..31cde63 100644
--- a/src/watchdog.hpp
+++ b/src/watchdog.hpp
@@ -71,7 +71,7 @@
              uint64_t defaultInterval = 0) :
         WatchdogInherits(bus, objPath),
         bus(bus), actionTargetMap(std::move(actionTargetMap)),
-        fallback(std::move(fallback)), minInterval(minInterval),
+        fallback(fallback), minInterval(minInterval),
         timer(event, std::bind(&Watchdog::timeOutHandler, this)),
         objPath(objPath)
     {
@@ -148,7 +148,7 @@
      *  @return: interval that was set
      *
      */
-    uint64_t interval(uint64_t value);
+    uint64_t interval(uint64_t value) override;
 
     /** @brief Tells if the referenced timer is expired or not */
     inline auto timerExpired() const