Fix another bug in last commit (last one?)

src/xpdev/xpbeep.c

@@ -422,7 +422,7 @@ BOOL xptone(double freq, DWORD duration, enum WAVE_SHAPE shape)
 
 	/* Prepare for next note */
 	curr_wh=1-curr_wh;
-	memset(wave[curr_wh], 128, sizeof(wave));	/* Ensure that if silence DOES timeout, you still get silence */
+	memset(wave[curr_wh], 128, sizeof(wave[0]));	/* Ensure that if silence DOES timeout, you still get silence */
 	wh=&wh_bufs[curr_wh];
 	waveOutWrite(waveOut, wh, sizeof(wh_bufs[0]));