decoder/Control: inline WaitForDecoder()

src/decoder/Control.cxx

@@ -41,12 +41,6 @@ DecoderControl::~DecoderControl() noexcept
 }
 
 void
-DecoderControl::WaitForDecoder(std::unique_lock<Mutex> &lock) noexcept
-{
-	client_cond.wait(lock);
-}
-
-void
 DecoderControl::SetReady(const AudioFormat audio_format,
 			 bool _seekable, SignedSongTime _duration) noexcept
 {

src/decoder/Control.hxx

@@ -215,7 +215,9 @@ public:
 	 *
 	 * Caller must hold the lock.
 	 */
-	void WaitForDecoder(std::unique_lock<Mutex> &lock) noexcept;
+	void WaitForDecoder(std::unique_lock<Mutex> &lock) noexcept {
+		client_cond.wait(lock);
+	}
 
 	bool IsIdle() const noexcept {
 		return state == DecoderState::STOP ||