winealsa.drv: Fix a memory leak

[Andrew Talbot]

Changelog:
    winealsa.drv: Fix a memory leak.

diff --git a/dlls/winealsa.drv/midi.c b/dlls/winealsa.drv/midi.c
index f5e98ed..26e1623 100644
--- a/dlls/winealsa.drv/midi.c
+++ b/dlls/winealsa.drv/midi.c
@@ -1018,6 +1018,7 @@ static DWORD modLongData(WORD wDevID, LP
     default:
 	WARN("Technology not supported (yet) %d !\n",
 	     MidiOutDev[wDevID].caps.wTechnology);
+	HeapFree(GetProcessHeap(), 0, lpNewData);
 	return MMSYSERR_NOTENABLED;
     }