SWDEV-292018 - Make sure start event is done

HSA signal callback order is undefined. Make sure start event is
also done before calculating the elapsed time.

Change-Id: Ic69bfe336b20cd62ef35194261a5d0d234bc65ce

hipamd/src/hip_event.cpp

@@ -116,6 +116,7 @@ hipError_t Event::elapsedTime(Event& eStop, float& ms) {
   } else {
     // Note: with direct dispatch eStop.ready() relies on HW event, but CPU status can be delayed.
     // Hence for now make sure CPU status is updated by calling awaitCompletion();
+    event_->awaitCompletion();
     eStop.event_->awaitCompletion();
     ms = static_cast<float>(eStop.time() - time())/1000000.f;
   }