- shut down WildMidi when exiting.

The pointless error message in WildMidi_Shutdown was removed to keep the rest of the code simple and allowing to call this even when the device never was used.

src/sound/i_music.cpp

@@ -189,6 +189,7 @@ void I_ShutdownMusic(void)
 		assert (currSong == NULL);
 	}
 	Timidity::FreeAll();
+	WildMidi_Shutdown();
 #ifdef _WIN32
 	I_ShutdownMusicWin32();
 #endif // _WIN32

src/wildmidi/wildmidi_lib.cpp

@@ -4261,8 +4261,8 @@ WildMidi_GetInfo(midi * handle) {
 
 WM_SYMBOL int WildMidi_Shutdown(void) {
 	if (!WM_Initialized) {
-		_WM_ERROR(__FUNCTION__, __LINE__, WM_ERR_NOT_INIT, NULL, 0);
+		// No error if trying to shut down an uninitialized device.
-		return -1;
+		return 0;
 	}
 	while (first_handle) {
 		/* closes open handle and rotates the handles list. */