general: Use deducation guides for std::lock_guard and std::unique_lock

Since C++17, the introduction of deduction guides for locking facilities
means that we no longer need to hardcode the mutex type into the locks
themselves, making it easier to switch mutex types, should it ever be
necessary in the future.

src/core/core_cpu.cpp

@@ -22,7 +22,7 @@
 namespace Core {
 
 void CpuBarrier::NotifyEnd() {
-    std::unique_lock<std::mutex> lock(mutex);
+    std::unique_lock lock{mutex};
     end = true;
     condition.notify_all();
 }
@@ -34,7 +34,7 @@ bool CpuBarrier::Rendezvous() {
     }
 
     if (!end) {
-        std::unique_lock<std::mutex> lock(mutex);
+        std::unique_lock lock{mutex};
 
         --cores_waiting;
         if (!cores_waiting) {
@@ -131,7 +131,7 @@ void Cpu::Reschedule() {
 
     reschedule_pending = false;
     // Lock the global kernel mutex when we manipulate the HLE state
-    std::lock_guard<std::recursive_mutex> lock(HLE::g_hle_lock);
+    std::lock_guard lock{HLE::g_hle_lock};
     scheduler->Reschedule();
 }