ALSA: pcm: Unexport snd_pcm_sgbuf_ops_page

The helper is no longer referred after the recent code refactoring.
Drop the export for saving some bits and future misuse.
Acked-by: NMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20191108094641.20086-9-tiwai@suse.deSigned-off-by: NTakashi Iwai <tiwai@suse.de>

include/sound/pcm.h

@@ -1236,14 +1236,6 @@ static inline int snd_pcm_lib_alloc_vmalloc_32_buffer
  */
 #define snd_pcm_substream_sgbuf(substream) \
 	snd_pcm_get_dma_buf(substream)->private_data
-
-struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream,
-				    unsigned long offset);
-#else /* !SND_DMA_SGBUF */
-/*
- * fake using a continuous buffer
- */
-#define snd_pcm_sgbuf_ops_page	NULL
 #endif /* SND_DMA_SGBUF */
 
 /**

sound/core/pcm_local.h

@@ -67,4 +67,9 @@ static inline void snd_pcm_timer_done(struct snd_pcm_substream *substream) {}
 void __snd_pcm_xrun(struct snd_pcm_substream *substream);
 void snd_pcm_group_init(struct snd_pcm_group *group);
 
+#ifdef CONFIG_SND_DMA_SGBUF
+struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream,
+				    unsigned long offset);
+#endif
+
 #endif	/* __SOUND_CORE_PCM_LOCAL_H */

sound/core/pcm_memory.c

@@ -255,7 +255,7 @@ void snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
 EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
 
 #ifdef CONFIG_SND_DMA_SGBUF
-/**
+/*
  * snd_pcm_sgbuf_ops_page - get the page struct at the given offset
  * @substream: the pcm substream instance
  * @offset: the buffer offset
@@ -273,7 +273,6 @@ struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigne
 		return NULL;
 	return sgbuf->page_table[idx];
 }
-EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
 #endif /* CONFIG_SND_DMA_SGBUF */
 
 /**