test/watchdog: Use a unique_ptr for the watchdog

This lets us change out the watchdog with a watchdog constructed using
different parameters. Currently this functionality is not used, but it
is needed for a future change.

Change-Id: Ie1e7fbf2c7fc8bf2949237f2535177ecd46944a0
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/watchdog_test.hpp b/test/watchdog_test.hpp
index e332260..beeda66 100644
--- a/test/watchdog_test.hpp
+++ b/test/watchdog_test.hpp
@@ -1,5 +1,6 @@
 #include <timer_test.hpp>
 #include <chrono>
+#include <memory>
 #include <watchdog.hpp>
 
 using namespace std::chrono;
@@ -12,8 +13,9 @@
         // Gets called as part of each TEST_F construction
         WdogTest()
             : bus(sdbusplus::bus::new_default()),
-              wdog(bus, TEST_PATH, eventP),
-              defaultInterval(milliseconds(wdog.interval())),
+              wdog(std::make_unique<phosphor::watchdog::Watchdog>(
+                      bus, TEST_PATH, eventP)),
+              defaultInterval(milliseconds(wdog->interval())),
               defaultDrift(30)
         {
             // Check for successful creation of
@@ -21,14 +23,14 @@
             EXPECT_GE(rc, 0);
 
             // Initially the watchdog would be disabled
-            EXPECT_FALSE(wdog.enabled());
+            EXPECT_FALSE(wdog->enabled());
         }
 
         //sdbusplus handle
         sdbusplus::bus::bus bus;
 
         // Watchdog object
-        phosphor::watchdog::Watchdog wdog;
+        std::unique_ptr<phosphor::watchdog::Watchdog> wdog;
 
         // This is the default interval as given in Interface definition
         milliseconds defaultInterval;