Fix incomplete forward declaration of struct AUDIO_OUT

* See also:
  #15

Author: SoapGentoo

examples/audio_out.c

@@ -43,7 +43,7 @@
 
 #define	ALSA_MAGIC		MAKE_MAGIC ('L', 'n', 'x', '-', 'A', 'L', 'S', 'A')
 
-typedef struct
+typedef struct AUDIO_OUT
 {	int magic ;
 	snd_pcm_t * dev ;
 	int channels ;

examples/audio_out.h

@@ -6,7 +6,7 @@
 ** file at : https://github.com/erikd/libsamplerate/blob/master/COPYING
 */
 
-typedef	struct AUDIO_OUT_s AUDIO_OUT ;
+typedef	struct AUDIO_OUT AUDIO_OUT ;
 
 typedef int (*get_audio_callback_t) (void *callback_data, float *samples, int frames) ;