ALSA: pcm: Remove snd_pcm_lib_preallocate_dma_free()

Since commit d4cfb30f ("ALSA: pcm: Set per-card upper limit of PCM
buffer allocations") snd_pcm_lib_preallocate_dma_free() is a single line
function that has one caller, which is another single line function.

Clean this up a bit and remove snd_pcm_lib_preallocate_dma_free() and
directly call do_free_pages() from snd_pcm_lib_preallocate_free(). This is
a bit less boilerplate.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20201218153400.18394-1-lars@metafoo.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_memory.c

@@ -89,14 +89,6 @@ static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t siz
 	return 0;
 }
 
-/*
- * release the preallocated buffer if not yet done.
- */
-static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream)
-{
-	do_free_pages(substream->pcm->card, &substream->dma_buffer);
-}
-
 /**
  * snd_pcm_lib_preallocate_free - release the preallocated buffer of the specified substream.
  * @substream: the pcm substream instance
@@ -105,7 +97,7 @@ static void snd_pcm_lib_preallocate_dma_free(struct snd_pcm_substream *substream
  */
 void snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream)
 {
-	snd_pcm_lib_preallocate_dma_free(substream);
+	do_free_pages(substream->pcm->card, &substream->dma_buffer);
 }
 
 /**