Remove unused apb_prepare function

ChangeLog

@@ -6032,4 +6032,6 @@
 	  audio buffer queuing (2013-11-10).
 	* arch/arm/src/sam34 and arch/arm/include/sam34:  Basic support for
 	  the Atmal SAM4E family.  From Mitko (2013-11-11).
+	* libc/audio/lib_buffer.c:  Remove unused apb_prepare() function
+	  (2013-11-11).
 

include/nuttx/audio/audio.h

@@ -670,9 +670,7 @@ int audio_register(FAR const char *name, FAR struct audio_lowerhalf_s *dev);
  *
  * Description:
  *   Allocated an AP Buffer and prepares it for use.  This allocates a dynamically
- *   allocated buffer that has no special DMA capabilities.  If a static buffer
+ *   allocated buffer that has no special DMA capabilities.
- *   or a buffer with DMA ability is needed, then it must be allocated manually
- *   and then call apb_prepare, passing it the allocated memory.
  *
  * Input parameters:
  *   bufdesc:   Pointer to a buffer descriptor
@@ -684,28 +682,6 @@ int audio_register(FAR const char *name, FAR struct audio_lowerhalf_s *dev);
 
 int apb_alloc(FAR struct audio_buf_desc_s *bufdesc);
 
-/****************************************************************************
- * Name: abp_prepare
- *
- * Description:
- *   Prepare a pre-allocated AP Buffer for use in the Audio Pipeline.
- *
- * Input parameters:
- *   apb - The pre-allocated AP Buffer
- *   size - The size of the pre-allocated buffer (for verification)
- *   allocmode - Indicates if the buffer is static or dynamic memory
- *   format - The format of samples to be used in the buffer
- *   subformat - The sub-format of samples
- *   maxsamples - The size, in samples, of the buffer
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-void apb_prepare(struct ap_buffer_s *apb, int8_t allocmode, uint8_t format,
-                 uint8_t subformat, apb_samp_t maxsamples);
-
 /****************************************************************************
  * Name: apb_free
  *

libc/audio/lib_buffer.c

@@ -153,19 +153,6 @@ int apb_alloc(FAR struct audio_buf_desc_s *bufdesc)
   return ret;
 }
 
-/****************************************************************************
- * Name: apb_prepare
- *
- * Prepare an AP Buffer for use in the Audio Pipeline.
- *
- ****************************************************************************/
-
-void apb_prepare(FAR struct ap_buffer_s *apb, int8_t allocmode, uint8_t format,
-                 uint8_t subformat, apb_samp_t maxsamples)
-{
-  /* Perform a reference count decrement and possibly release the memory */
-}
-
 /****************************************************************************
  * Name: apb_free
  *