SDL_n3dsaudio.h: use triple buffering

src/audio/n3ds/SDL_n3dsaudio.h

@@ -27,7 +27,7 @@
 /* Hidden "this" pointer for the audio functions */
 #define _THIS SDL_AudioDevice *this
 
-#define NUM_BUFFERS 2 /* -- Don't lower this! */
+#define NUM_BUFFERS 3 /* -- Minimum 2! */
 
 struct SDL_PrivateAudioData
 {