event/*, ...: make GetEventLoop() const

src/lib/curl/Global.hxx

@@ -50,7 +50,7 @@ class CurlGlobal final {
 public:
 	explicit CurlGlobal(EventLoop &_loop);
 
-	EventLoop &GetEventLoop() noexcept {
+	auto &GetEventLoop() const noexcept {
 		return timeout_event.GetEventLoop();
 	}
 

src/lib/dbus/Glue.hxx

@@ -42,7 +42,7 @@ public:
 		DisconnectIndirect();
 	}
 
-	EventLoop &GetEventLoop() noexcept {
+	auto &GetEventLoop() const noexcept {
 		return watch.GetEventLoop();
 	}
 

src/lib/dbus/Watch.hxx

@@ -102,7 +102,7 @@ public:
 
 	void Shutdown() noexcept;
 
-	EventLoop &GetEventLoop() noexcept {
+	auto &GetEventLoop() const noexcept {
 		return defer_dispatch.GetEventLoop();
 	}
 

src/lib/nfs/Connection.hxx

@@ -161,9 +161,7 @@ public:
 		return export_name.c_str();
 	}
 
-	EventLoop &GetEventLoop() noexcept {
-		return SocketMonitor::GetEventLoop();
-	}
+	using SocketMonitor::GetEventLoop;
 
 	/**
 	 * Ensure that the connection is established.  The connection

src/lib/nfs/FileReader.hxx

@@ -69,7 +69,7 @@ public:
 	NfsFileReader() noexcept;
 	~NfsFileReader() noexcept;
 
-	EventLoop &GetEventLoop() noexcept {
+	auto &GetEventLoop() const noexcept {
 		return defer_open.GetEventLoop();
 	}
 

src/lib/upnp/Discovery.cxx

@@ -272,7 +272,7 @@ UPnPDeviceDirectory::~UPnPDeviceDirectory() noexcept
 }
 
 inline EventLoop &
-UPnPDeviceDirectory::GetEventLoop() noexcept
+UPnPDeviceDirectory::GetEventLoop() const noexcept
 {
 	return curl->GetEventLoop();
 }

src/lib/upnp/Discovery.hxx

@@ -168,7 +168,7 @@ public:
 	UPnPDeviceDirectory(const UPnPDeviceDirectory &) = delete;
 	UPnPDeviceDirectory& operator=(const UPnPDeviceDirectory &) = delete;
 
-	EventLoop &GetEventLoop() noexcept;
+	EventLoop &GetEventLoop() const noexcept;
 
 	void Start();