ASoC: wm_adsp: wm_adsp_buf_alloc should use kfree in error path

buf was allocated by kzalloc() so it should be passed to kfree()
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm_adsp.c

@@ -187,7 +187,7 @@ static struct wm_adsp_buf *wm_adsp_buf_alloc(const void *src, size_t len,
 
 	buf->buf = vmalloc(len);
 	if (!buf->buf) {
-		vfree(buf);
+		kfree(buf);
 		return NULL;
 	}
 	memcpy(buf->buf, src, len);