src: mark more ctors as explicit

src/core/thread/mpsc_queue.inl

@@ -21,7 +21,7 @@ struct MPSCQueue
 	Mutex _mutex;
 
 	///
-	MPSCQueue(Allocator &a)
+	explicit MPSCQueue(Allocator &a)
 		: _queue(a)
 	{
 	}

src/core/thread/spsc_queue.inl

@@ -26,7 +26,7 @@ struct SPSCQueue
 	T *_queue;
 
 	///
-	SPSCQueue(Allocator &a)
+	explicit SPSCQueue(Allocator &a)
 		: _tail(0)
 		, _head(0)
 		, _allocator(&a)

src/device/device_event_queue.inl

@@ -20,7 +20,7 @@ struct DeviceEventQueue
 	QueuePushFunction _queue_push_function;
 
 	///
-	DeviceEventQueue(QueuePushFunction fn)
+	explicit DeviceEventQueue(QueuePushFunction fn)
 		: _queue_push_function(fn)
 	{
 	}