Add g_ prefix to is_audio_initialized

src/play_sound.c

@@ -7,7 +7,7 @@
 SM64PlaySoundFunctionPtr g_play_sound_func = NULL;
 
 extern void play_sound( uint32_t soundBits, f32 *pos ) {
-    if ( is_audio_initialized ) {
+    if ( g_is_audio_initialized ) {
         DEBUG_PRINT("$ play_sound(%d) request %d; pos %f %f %f\n", soundBits,sSoundRequestCount,pos[0],pos[1],pos[2]);
         sSoundRequests[sSoundRequestCount].soundBits = soundBits;
         sSoundRequests[sSoundRequestCount].position = pos;