Call systemd target on timer expiration

User can pass an optional command line argument stating which
systemd target needs to be called on timer expiration. The timeout
handler will make sure that the systemd target is started prior to
exiting.

Change-Id: I37213ab28ad4166a47920dcb3dc79769c7f2af1a
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
diff --git a/mainapp.cpp b/mainapp.cpp
index b9e6121..7751aa9 100644
--- a/mainapp.cpp
+++ b/mainapp.cpp
@@ -72,7 +72,8 @@
     bus.attach_event(eventP.get(), SD_EVENT_PRIORITY_NORMAL);
 
     // Create a watchdog object
-    phosphor::watchdog::Watchdog watchdog(bus, path.c_str(), eventP);
+    phosphor::watchdog::Watchdog watchdog(bus, path.c_str(),
+                                          eventP, std::move(target));
 
     // Claim the bus
     bus.request_name(service.c_str());