Fixed documentation for SDL_SetAudioStreamGetCallback()

Fixes https://github.com/libsdl-org/SDL/issues/10633

include/SDL3/SDL_audio.h

@@ -1557,7 +1557,7 @@ typedef void (SDLCALL *SDL_AudioStreamCallback)(void *userdata, SDL_AudioStream
  * Setting a NULL function turns off the callback.
  *
  * \param stream the audio stream to set the new callback on.
- * \param callback the new callback function to call when data is added to the
+ * \param callback the new callback function to call when data is requested from the
  *                 stream.
  * \param userdata an opaque pointer provided to the callback for its own
  *                 personal use.