Core: Make use of C++17 deduction guides with locks

C++17 allows omitting the mutex type, which makes for both less reading
and more flexibility (e.g. The mutex type can change and all occurrences
don't need to be updated).

Source/Core/Core/CoreTiming.cpp

@@ -141,7 +141,7 @@ void Init()
 
 void Shutdown()
 {
-  std::lock_guard<std::mutex> lk(s_ts_write_lock);
+  std::lock_guard lk(s_ts_write_lock);
   MoveEvents();
   ClearPendingEvents();
   UnregisterAllEvents();
@@ -149,7 +149,7 @@ void Shutdown()
 
 void DoState(PointerWrap& p)
 {
-  std::lock_guard<std::mutex> lk(s_ts_write_lock);
+  std::lock_guard lk(s_ts_write_lock);
   p.Do(g.slice_length);
   p.Do(g.global_timer);
   p.Do(s_idled_cycles);
@@ -265,7 +265,7 @@ void ScheduleEvent(s64 cycles_into_future, EventType* event_type, u64 userdata,
                     *event_type->name);
     }
 
-    std::lock_guard<std::mutex> lk(s_ts_write_lock);
+    std::lock_guard lk(s_ts_write_lock);
     s_ts_queue.Push(Event{g.global_timer + cycles_into_future, 0, userdata, event_type});
   }
 }